Unplanned revascularization and major adverse cardiac events in spontaneous coronary artery disease patients: insights from a cardiac center

Abstract

Aim

Spontaneous Coronary Artery Disease (SCAD) is a rare condition that mimics acute coronary syndrome and can lead to serious complications. This study evaluates SCAD characteristics, Major Adverse Cardiac Event (MACE) predictors, revascularization needs, and treatment outcomes.

Materials and methods

The single cardiac center, retrospective cohort study analyzed patients diagnosed with coronary artery dissection during coronary angiography between January 2014 and December 2019.

Results

Of 86 patients, 24(27.9%) experienced early MACE. Diffuse dissections (62.5% vs. 37.5%, p = 0.027) and ostium-involving dissections (33.3% vs. 8.1%, p = 0.006) were more frequent in the MACE group. Female patients (58.3% vs. 21.0%, p = 0.001) and those with lower pre-procedural ejection fraction (EF) (44.1 ± 13.5 vs. 55.0 ± 8.8, p = 0.004) or higher neutrophil to lymphocyte ratio (NLR) (5.59 ± 3.67 vs. 3.60 ± 2.46, p = 0.005) had a higher risk. Ostium-involving dissections (OR(Odds Ratio) = 9.41, p = 0.024) and low EF (OR = 0.931, p = 0.040) were independent predictors of MACE. Initial medical treatment is associated with higher unplanned revascularization compared to percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) (p = 0.030). Coronary tortuosity (p = 0.006) and spot lesions (p = 0.005) were associated with late revascularization.

Conclusion

High early MACE after SCAD is associated with female gender, high NLR, and low EF. Diffuse and ostium-involving dissections significantly increase the risk of MACE. Initial treatment has been shown to influence early revascularization. while coronary features like tortuosity predict long-term outcomes.

Clinical Trial Number

Not applicable.

Introduction and aim

Spontaneous Coronary Artery Dissection (SCAD) was first described in 1931 by Pretty as a non-traumatic and non-iatrogenic form of coronary artery dissection [1]. Although SCAD can affect individuals of both sexes, it is more commonly reported in women, particularly during the peripartum period [2, 3].

The global prevalence of SCAD is estimated between 0.07% and 1.1% of all coronary angiographies, with a higher incidence in patients undergoing angiography for suspected acute coronary syndrome, where SCAD accounts for approximately 1–4% of cases [4, 5]. Furthermore, it has been identified in 0.5% of sudden cardiac death cases in autopsy studies [6]. Clinically, SCAD typically presents as acute coronary syndrome—ranging from STEMI(ST Elevated Myocardial Infarction) to NSTEMI(Non ST Elevated Myocardial Infarction) and unstable angina—and may lead to complications such as ventricular arrhythmias, cardiogenic shock, and, albeit rarely, sudden cardiac death [6–8].

While the exact etiology remains unclear, several potential triggers have been proposed, including emotional or physical stress, hormonal fluctuations (e.g., pregnancy), and stimulant or recreational drug use [7].

Although conservative management is generally preferred in SCAD, some patients may require revascularization during their clinical course. A recent meta-analysis compared invasive strategies with optimal medical therapy, but data from high-volume centers remain limited [9].

This study aims to identify clinical and angiographic predictors of unplanned revascularization in SCAD patients, and to explore revascularization needs beyond MACE, with the goal of improving risk stratification and guiding treatment strategies in real-world practice.

Materials and methods

Study location, design, and duration

This single-center, retrospective, and observational cohort study aims to analyze the demographic, anatomical, laboratory, and clinical characteristics of patients with coronary artery dissection diagnosed during coronary angiography conducted under both elective and emergency conditions between January 2014 and December 2019 at Dr. Siyami Ersek Thoracic Cardiac and Vascular Surgery Training and Research Hospital, Istanbul. The study also tracks the mid-to long-term outcomes of selected treatment strategies.

Patients selection

Patients were selected based on a keyword search (“dissection” and/or “filling defect”) applied to all coronary angiography reports (n = 54,501). Matches were manually reviewed by two physicians to confirm spontaneous, non-iatrogenic dissection. Only one unique coronary angiography per patient was retained. This was not a consecutive series, but a filtered, criterion-based selection. After applying these criteria, a total of 86 cases of spontaneous (non-traumatic, non-iatrogenic) coronary artery dissection were identified.

Inclusion and exclusion criteria

Patients aged > 18 years who underwent coronary angiography during the study period, with available images and clinical data, and no history of cardiac surgery or PCI (balloon/stent), were included.

Patients were excluded if they had undergone open-heart surgery, had multivessel disease with ≥ 50% stenosis in any non-dissected coronary artery, had prior PCI or coronary stents, or experienced iatrogenic dissection during angiography. Specifically, iatrogenic dissections occurring during PCI were excluded to ensure a focus on spontaneous cases (SCAD), which differ markedly from iatrogenic dissections in pathophysiology, clinical course, and management.

To ensure a more homogeneous cohort, patients with moderate-to-severe multivessel disease or diffuse atherosclerosis were also excluded. However, this may limit the generalizability of the findings, as such cases are common in real-world clinical practice.

Data collection

Following patient selection, clinical histories, admission types, laboratory results, and treatment strategies were retrieved from the hospital database. Left ventricular EF was assessed by transthoracic echocardiography before and after the procedure as part of routine care.

Coronary dissections were reviewed angiographically, focusing on vessel involvement, ostial location, and dissection type. Lesions ≥ 2 cm were classified as diffuse; those < 2 cm as focal (spot). Although the Saw classification (Type 1–3) is a widely accepted angiographic system for SCAD lesion typing, it was not fully applied in this study. While Type 1 and Type 2 lesions are typically identifiable on coronary angiography, Type 3 lesions require intracoronary imaging (e.g., IVUS(Intravascular Ultrasound) or OCT(Optic Coherence Tomography)) to differentiate from atherosclerotic disease. Since advanced imaging was not routinely available in our cohort, we instead categorized lesion morphology based on anatomical features such as lesion length (spot vs. diffuse), ostial involvement, and tortuosity [10]. Significant stenosis was defined as ≥ 70% luminal narrowing.

In-hospital events were recorded from patient files. After discharge, follow-up was conducted via phone using contact information from hospital records and the national health database. Patients were asked about cardiac symptoms, hospitalizations, and whether they had undergone coronary angiography elsewhere. For those with recurrent events, further details were collected.

Relatives of three deceased patients were successfully contacted. Four others were excluded from long-term follow-up due to lack of contact, despite being listed as deceased or alive in the national system.

Definition of clinical endpoints

The primary clinical endpoint was the occurrence of major adverse cardiac events MACE and Unplanned Revascularization during follow-up. MACE during follow-up were defined as acute myocardial infarction, revascularization (PCI or CABG), congestive heart failure, or cardiac death. Unplanned revascularization was defined as the need for PCI or CABG during follow-up in patients who were initially managed conservatively and did not meet the criteria for revascularization during the index coronary angiography. This decision was based on clinical evidence of recurrent ischemia, including recurrent chest pain, new ECG changes, or ischemia confirmed by non-invasive tests. Procedural failure during the initial angiography was not included in this definition.

Secondary endpoints included in-hospital mortality, long-term all-cause mortality, and cardiac-specific mortality.

Follow-up

After discharge, patients were contacted through available contact details in the database, and cardiac performance was assessed. Patients were also queried regarding readmissions to other health facilities for cardiovascular issues and repeat angiography. Three patients who died were contacted through first-degree relatives. Four patients were excluded from long-term analysis due to difficulties contacting them, even though their death status was known from national databases.

In our study, the 30-day period from the onset of symptoms was defined as early MACE, while the period between 30 and 90 days was considered mid-term. However, all complications occurring beyond 30 days were categorized as part of the mid-to-long-term MACE period, and the results were evaluated accordingly. In the long-term follow-up, MACE was defined as acute myocardial infarction, PCI or CABG for revascularization, development of congestive heart failure, and death from cardiovascular causes.

Statistical evaluation

Descriptive statistics were presented as mean ± standard deviation or median with interquartile range (IQR), as appropriate. Categorical variables were expressed as frequencies and percentages. Normality of continuous variables was assessed using the Shapiro-Wilk test and visual inspection of histograms. For group comparisons, the Student’s t-test was used for normally distributed variables, and the Mann-Whitney U test for non-normal distributions. Categorical variables were compared using the Chi-square test.

Variables with significant or borderline significance in univariate analysis were included in multivariate analysis using binary logistic regression. A p-value ≤ 0.05 was considered statistically significant.

Results

Study population and baseline characteristics

Between January 2014 and December 2019, 86 patients diagnosed with SCAD were treated at Dr. Siyami Ersek Hospital, a high-volume cardiac center. The cohort included 59 men (68.6%) and 27 women (31.4%), with a mean age of 50.8 ± 11.1 years (range: 23–81).

Comorbidities and risk factors

Diabetes mellitus was present in 28 patients (32.6%), hypertension in 23 (26.7%), and hyperlipidemia in 23 (26.7%). A positive family history of cardiovascular disease was noted in 36 patients (41.9%), and 60 (69.8%) were active smokers. Three postpartum women (3.5% of the total cohort, 11.1% of the female subgroup) were also identified.

Clinical presentation and ECG findings

SCAD presented as STEMI in 35 patients (40.7%), NSTEMI in 29 (33.7%), unstable angina in 19 (22.1%), and was incidentally detected in 3 (3.5%). Electrocardiographic findings included normal sinus rhythm in 41 patients (47.7%), anterior MI(Myocardial Infarction) in 19 (22.1%), inferior MI in 13 (15.1%), lateral wall MI in 3 (3.5%), ST depression in 4 (4.7%), and arrhythmias in 6 patients (7%). (Fig. 1)

Fig. 1.

Pie charts showing the initial clinical presentation and electrocardiographic findings of patients diagnosed with spontaneous coronary artery dissection (SCAD). The most common hospital presentation was STEMI (40.7%), followed by non-STEMI (33.7%) and unstable angina (22.1%). Normal simus rhythm was the most frequent EKG finding (47.7%), with anterior MI and inferior MI following

Dissection characteristics and localization

A single coronary artery was involved in 83 patients (96.5%), while 3 (3.5%) had multivessel dissections. The left anterior descending artery (LAD) was affected in 42 cases (48.8%), and the right coronary artery (RCA) in 6 (7.0%). Among multivessel cases, two involved both the left main coronary artery (LMCA) and LAD, and one involved the LAD and RCA. Dissections involving the ostium were observed in 13 patients (15.1%), most commonly at the LAD ostium (n = 8, 61.5% of ostial cases). (Table 1)

Table 1.

Localization of coronary artery dissections

Coronary Artery	Localization	Number (n)	Percentage (%)
Single SCAD (96,5%, n = 83)
LAD	Proximal / Mid / Distal	42 [21/20/1]	48,8 [50,0/47,6/2,4]
RCA	Proximal / Mid / Distal	35 [17/16/2]	40,7 [48,6/45,7/5,7]
Cx	Proximal / Mid	4 [2/2]	4,7 [50,0/50,0]
LMCA	Proximal / Distal	2 [1/1]	2,3 [50,0/50,0]
Multiple SCAD (3.5%, n = 3)
LMCA + LAD	Distal LMCA + Proximal LAD / Distal LMCA + Mid LAD	2 [1/1]	2,3 [50,0/50,0]
LAD + RCA	Mid LAD + Proximal RCA	1	1,3 [100]
Ostial-Involving SCAD (15,1%, n = 13)
LAD	Ostium	8	61,5
RCA	Ostium	4	30,8
LMCA + LAD	Ostium	1	7,7

^*: The percentage of ostial-origin dissections (15,1%) represents the proportion of all coronary artery dissections (n = 86). SCAD: Spontan Coronary Artery Dissections; LMCA: Left Main Coronary Artery; LAD: Left Anterior Descending Artery; Cx: Circumflex Artery; RCA: Right Coronary Artery

Significant stenosis and plaque association

Severe stenosis (≥ 70% luminal narrowing) caused by dissection was observed in 77.8% (n = 67) of cases. Plaque was detected in 30.2% (n = 26) of dissected coronary arteries. Among these, severe stenosis was absent in 7.7% (n = 2) but present in 92.3% (n = 24). Conversely, severe stenosis was observed in 71.7% (n = 43) of the 60 patients without plaques in their dissected arteries. Dissections in plaque-containing arteries were more likely to result in severe stenosis compared to those without plaques (p = 0.034). (Table 2)

Table 2.

Association between significant stenosis and plaque presence

	Present of Plaque (n = 26)	Absent of plaque(n = 60)	p-value
Significant Stenosis(n = 67)	92,3% (n = 24)	71,7% (n = 43)	0,034
No Significant Stenozis(n = 19)	7,7%(n = 2)	28,3%(n = 17)
Diffuse Lesion (n = 38)	38,5% (n = 10)	46,7% (n = 28)	0,482
Spot Lesion(n = 48)	61,5% (n = 16)	53,3% (n = 32)

*Lesions longer than 2 cm were classified as diffuse, while those shorter than 2 cm were classified as spot lesions

*Significant stenosis refers to dissections that cause more than 70% luminal narrowing

In SCAD patients who developed in-hospital mortality, all 5 deceased patients had dissection in a single artery. Among these five patients, 60% (n = 3) had LAD dissection, 20% (n = 1) had LMCA dissection, and 20% (n = 1) had RCA dissection. Severe stenosis was present in 80% (n = 4) of these patients, while no severe stenosis was found in 20% (n = 1). Dissections causing severe stenosis were not statistically significantly associated with in-hospital mortality (p = 1.0).

SCAD and early MACE

MACE occurred in 27.9% (n = 24) of patients during the early period following SCAD. Among these, 11.6% (n = 10) required revascularization, while 5.8% (n = 5) resulted in in-hospital mortality. Low cardiac output syndrome was observed in 3.5% (n = 3), with intra-aortic balloon pump (IABP) implantation required in 66.6% (n = 2) of these cases. Malignant arrhythmias occurred in 2.3% (n = 2), with implantable cardioverter defibrillator placement in 50% (n = 1). Additionally, 2.3% (n = 2) underwent cardiopulmonary resuscitation, and tamponade was identified in 1.2% (n = 1). Non-cardiac MACE, including cerebrovascular events (CVE) accounted for 1.2% (n = 1). (Table 3)

Table 3.

Early and long term MACE characteristics

Outcome	Early MACE % (n = 24)	Mid-Long Term MACE % (n = 19)
Revascularization	11,6(n = 10)	22,1(n = 17)
Mortality	5,8(n = 5)	3,9(n = 3)*
Low Cardiac Output	3,5(n = 3)	2,6(n = 2)
Malignant Arrhythmia	2,3(n = 2)
CPR	2,3(n = 2)
Tamponade	1,2(n = 1)
CVE	1,2(n = 1)

^*characteristics of early mace were calculated based on 86 patients. for long term mace, patients who had previously died or were lost to follow-up were excluded, resulting in data from 77 patients. among the deceased, three patients had undergone revascularization prior to their exitus

CVE: cerebrovascular event; CPR: cardio pulmonary resuscitation

In patients who did not develop early MACE, the average age was 50.9 ± 11.0 years, while in those who developed MACE, the average age was 50.6 ± 11.6 years, with no significant difference (p = 0.915). Among the MACE group, 58.3% (n = 14) were female, which showed a significant difference (p = 0.001). The distribution of dissected coronary arteries in the MACE group was as follows: LMCA 4.2% (n = 1), LAD 41.7% (n = 10), RCA 50% (n = 12), and both LMCA and LAD together 4.2% (n = 1), with no significant difference (p = 0.555).

In the MACE group, 37.5% (n = 9) had coronary ectasia, 29.2% (n = 7) had thrombus, and 16.7% (n = 4) had tortuosity. In patients without MACE, 35.5% (n = 22) had ectasia, 25.8% (n = 16) had thrombus, and 12.9% (n = 8) had tortuosity, with no significant differences (p = 0.861; p = 0.752; p = 0.731).

Regarding comorbidities in the MACE group, DM(diabetes mellitus) was present in 41.7% (n = 19), hyperlipidemia in 16.7% (n = 4), smoking in 66.7% (n = 16), hypertension in 66.7% (n = 16), a family history of cardiac disease in 41.7% (n = 10), and postpartum status in 4.2% (n = 1). No significant differences were found between patients with and without MACE for these features. (Table 4)

Table 4.

Comparison of baseline characteristics and outcomes in patients with early and mid-long term major adverse cardiac events (MACE)

Parameter	No Early MACE (n = 62)	Early MACE (n = 24)	P-value	No Mid-Long Term MACE(n = 58)	Mid-Long Term MACE (n = 19)	P-value
Age (years)	50,9 ± 11,0	50,6 ± 11,6	0,915	49,7 ± 11,2	52,5 ± 12,1	> 0,05
Female Gender %	21,0 (n = 13)	58,3 (n = 14)	0,001	31,0 (n = 18)	26,3 (n = 5)	0,697
Diabetes Mellitus (DM) %	29,0 (n = 18)	41,7 (n = 19)	0,262	29,3 (n = 17)	36,8 (n = 7)	0,538
Hyperlipidemia (Hl) %	30,6 (n = 19)	16,7 (n = 4)	0,189	22,4 (n = 13)	26,8 (n = 7)	0,238
Smoking %	71,0 (n = 44)	66,7 (n = 16)	0,697	74,1 (n = 43)	63,2 (n = 12)	0,358
Hypertension (HT) %	43,5 (n = 27)	66,7 (n = 16)	0,054	48,3 (n = 28)	52,6 (n = 10)	0,742
Family History %	41,9 (n = 26)	41,7 (n = 10)	0,982	41,4 (n = 24)	52,6 (n = 10)	0,391
Postpartum%	3,2 (n = 2)	4,2 (n = 1)	1,000	3,4 (n = 2)	5,3 (n = 1)	1,000
Pre-procedure EF (mean)	55,0 ± 8,8	44,1 ± 13,5	0,004	52,7 ± 11,5	54,0 ± 9,1	0,749
Post-procedure EF (mean)	53,0 ± 8,4	48,3 ± 14,1	0,290	52,9 ± 9,8	53,0 ± 6,5	0,970
NLR(mean)	3,60 ± 2.46	5,59 ± 3,67	0,005	3,87 ± 2,53	3,6 ± 2,50	0,707
WBC(mean)	10,8 ± 3.5	12,3 ± 4,6	0,100
MPW/PLT(mean)	0,038 ± 0.014	0,040 ± 0,018	0,596
Ostium-Involving Dissection	8,1(n = 5)	33,3 (n = 8)	0,006
Lesion Length
Diffuse	37,1(n = 23)	62,5 (n = 15)	0.027
Spot	62,9 (n = 39)	37,5 (n = 9)
Dissected Coronary Artery
LMCA(n = 2)	1,6 (n = 1)	4,2 (n = 1)	0,555
LAD (n = 42)	51,6 (n = 32)	41,7(n = 10)
Cx(n = 4)	6,5 (n = 4)	0 (n = 0)
RCA (n = 35)	37,1 (n = 23)	50,0(n = 12)
LMCA + LAD(n = 2)	1,6 (n = 1)	4,2(n = 1)
LAD + RCA(n = 1)	1,6 (n = 1)	0 (n = 0)

NLR: Neutrophil to Lymphocyte Ratio; WBC: White Blood Cell; MPW: Mean Platelet Width PLT: Platelet Count; EF: Ejection Fraction(%)

Among MACE patients, diffuse dissections (lesion length more than 2 cm) were significantly more frequent than spot (less than 2 cm) dissections (62.5% vs. 37.5%, p = 0.027). Ostium-involving dissections were observed in 33.3% (n = 8) of MACE cases, compared to 8.1% in non-MACE cases (p = 0.006). (Table 4)

Pre-procedural EF was significantly lower in the MACE group compared to the non-MACE group (44.1 ± 13.5 vs. 55.0 ± 8.8, p = 0.004). Additionally, the NLR was elevated in the MACE group (5.59 ± 3.67 vs. 3.60 ± 2.46, p = 0.005). Multivariate analysis identified ostium-involving dissections (p = 0.024, OR = 9.41) and pre-procedural EF (p = 0.040, OR = 0.931) as independent predictors of early MACE. (Table 4)

Long-term MACE outcomes in SCAD patients

In evaluating long-term MACE, five patients who had died and four whose follow-up was inaccessible were excluded from the study. Thus, the analysis was conducted on 77 patients. Among the 77 patients who underwent medium-term follow-up, MACE occurred in 24.7% (n = 19). In the long-term follow-up, the median follow-up duration for these 77 patients was 1626 days (IQR: 1052–2167). The mean time to MACE development was 246.5 ± 149.5 days. In terms of MACE characteristics, 22.1% (n = 17) of the patients required revascularization, and of these, 17.6% (n = 3) had died from cardiac causes post-admission. Furthermore, 2.6% (n = 2) of the patients developed congestive heart failure during follow-up and were under medical management. (Table 3)

When comparing variables between patients with and without long-term MACE, there were no statistically significant differences in age, female gender, DM, hypertension, hyperlipidemia, smoking, family history, postpartum development of SCAD, NLR, or pre- and post-procedural EF (Table 4).

Treatment strategies and unplanned revascularization

Among non-MACE patients, 36 (58%) underwent stent implantation, 18 (29%) received medical therapy alone, and 8 (13%) underwent CABG. In the MACE group, the corresponding figures were 11 (45.8%) for stent placement, 11 (45.8%) for medical therapy, and 2 (8.3%) for CABG. No significant difference was observed between treatment modality and early MACE occurrence (p = 0.484). (Fig. 2)

Fig. 2.

Stacked bar chart demonstrating the distribution of major adverse cardiac events (MACE) by initial treatment strategy: percutaneous coronary intervention (PCI), medical therapy, and coronary artery bypass grafting (CABG). No statistically significant difference was observed between treatment modality and the occurrence of MACE (p = 0.484)

Unplanned revascularization, a subset of early MACE, occurred in 10 patients. Most had been initially treated medically (n = 7, 70%), while 3 (30%) had previously undergone PCI. Notably, none of the patients who underwent CABG experienced early unplanned revascularization (p = 0.030). (Fig. 3)

Fig. 3.

Bar graph depicting the proportion of patients requiring umplammed revascularization in the early phase after initial coronary angiography. The rate of revascularization was significantly higher among patients initially treated with medical therapy (p=0.03). Mean time to repeat angiography was 3.4 ± 2.4 days. Note: Graph showing patients requiring unplanned revascularization, a subgroup of early MACE, according to the initial treatment strategy (p=0.030). Revascularization occurred in a total of 10 patients, with the mean time to repeat coronary angiography calculated as 3.4 ± 2.4 days.

In the long-term, 19 patients developed MACE. At initial presentation, 11 of them (57.9%) had received PCI, 7 (36.8%) were treated medically, and 1 (5.3%) had undergone CABG. Similarly, among the 17 patients who eventually required late revascularization, 10 (58.8%) were initially treated with PCI, 6 (35.3%) with medical therapy, and 1 (5.9%) with CABG. However, no significant association was found between initial treatment strategy and long-term MACE (p = 0.700) or the need for later revascularization (p = 0.779).

These findings suggest that initial management may not be the key determinant of long-term outcomes in SCAD. Interestingly, neither medical therapy nor PCI at baseline significantly influenced the long-term risk of MACE or unplanned revascularization. This reinforces the notion that anatomical characteristics may be more critical than the initial treatment modality in predicting outcomes. It also highlights the limitations of current decision-making algorithms, which often rely heavily on clinical presentation rather than anatomical markers. Instead, anatomical factors seem to play a larger role. For instance, among the 60 patients who did not undergo revascularization, lesion types were evenly split: 30 had spot lesions (50.0%), and 30 had diffuse lesions (50.0%). In contrast, among the 17 patients who later required revascularization, 15 (88.2%) had spot lesions and only 2 (11.8%) had diffuse dissections—this difference was statistically significant (p = 0.005). Coronary tortuosity was also more common in the revascularization group (35.3% vs. 6.7%, p = 0.006), while ectasia was not significantly different. (Fig. 4).

Fig. 4.

Bar graphs presenting the relationship between umplammed revascularization during long-term follow-up and angiographic features, including lesion type (diffuse vs. spot), presence of coronary ectasia, and coronary tortuosity. Revascularization was significantly more frequent in patients with spot lesions (p=0.005), coronary ectasia (p=0.08), and absence of coronary tortuosity (p=0.006)

To further investigate, a subgroup analysis was conducted. Patients who required unplanned revascularization (n = 17) were similar in age (51.4 ± 12.4 vs. 50.2 ± 11.2 years, p = 0.690) and sex (female: 29.4% vs. 30.0%, p = 0.963) compared to those who did not. Comorbidities—including diabetes, hypertension, hyperlipidemia, smoking, and family history—showed no significant associations. Likewise, initial SCAD presentation (STEMI, NSTEMI, unstable angina, incidental) was not significantly different (p = 0.544).

However, angiographic features stood out: spot lesions were significantly more common in patients who later underwent revascularization (88.2% vs. 50.0%, p = 0.005), and tortuosity was again more frequent (35.3% vs. 6.7%, p = 0.006). Other variables such as ostial involvement, coronary ectasia, and thrombolytic therapy did not differ between groups. (Table 5)

Table 5.

Selected subgroup analysis of patients with and without unplanned revascularization

Variable	No Revascularization (n = 60)	Revascularization (n = 17)	p-value
Age (years)	50.2 ± 11.2	51.4 ± 12.4	0.690
Female sex	18 (30.0%)	5 (29.4%)	0.963
SCAD presentation - STEMI	24 (40.0%)	5 (29.4%)	0.544
NSTEMI	22 (36.7%)	5 (29.4%)
Unstable angina	12 (20.0%)	6 (35.3%)
Incidental	2 (3.3%)	1 (5.9%)
Lesion morphology - Diffuse	30 (50.0%)	2 (11.8%)	0.005
Spot	30 (50.0%)	15 (88.2%)
Coronary ectasia	18 (30.0%)	9 (52.9%)	0.080
Coronary tortuosity	4 (6.7%)	6 (35.3%)	0.006

Multivariate logistic regression identified lesion morphology and coronary tortuosity as independent predictors of unplanned revascularization. Spot lesion morphology was associated with lower risk (OR: 0.13; 95% CI: 0.03–0.63; p = 0.005), while tortuous anatomy significantly increased risk (OR: 7.64; 95% CI: 1.84–31.62; p = 0.006). Other variables—including sex, SCAD presentation type, and presence of ectasia—were not statistically significant. (Fig. 5).

Fig. 5.

Forest plot of independent predictors for unplanned revascularization in SCAD (n=77), based on multivariate logistic regression analysis. Spot lesion morphology was associated with reduced risk, whereas coronary tortuosity was associated with increased risk

Discussion

In this retrospective study, the prevalence of SCAD was 0.16%, aligning with previous reports that range from 0.1–1.1% [10, 11]. Although SCAD is often described as a condition affecting young women, our findings differ. A male predominance was observed, and most cases occurred in the 5th and 6th decades of life. Only 31.4% of our patients were female, which is lower than previously reported female rates: 51% in Daoulah et al. [12], 53.8% in Nishiguchi et al. [5], and 13.6% in Liu et al. [13].

This gender discrepancy may be explained by selection bias, as our study included only hospital-presenting patients. Women with atypical or mild symptoms might not have been diagnosed. Regional differences may also play a role, as most female-dominant cohorts are from Western populations. Our findings suggest SCAD should also be considered in male patients, and as awareness increases, the gender gap might narrow. Multicenter prospective studies are needed to explore this further.

Consistent with prior studies, the LAD was the most frequently affected artery in our patients (48.8%) [7, 14–16]. Interestingly, dissections originated from proximal segments in roughly half of the cases across LAD, RCA, and CX arteries. However, some studies report more frequent involvement of mid-to-distal segments [7]. This difference could be due to the limited use of intravascular imaging (e.g., IVUS, OCT) in our center, which may better localize intimal tears. Another possibility is retrograde hematoma spread, as proposed in the “outside-in” theory.

Although stenosis > 70% was not statistically linked to MACE or unplanned revascularization, it may still affect clinical decision-making. We believe these findings still contribute meaningfully to the literature.

In our cohort, atherosclerotic plaque was present in 30.2% of SCAD patients. While this did not significantly impact MACE, it was associated with more severe stenosis (p = 0.032). Interestingly, 61.5% of patients with plaque had spot-type lesions. These may progress more rapidly when plaque is absent, suggesting a different pathological mechanism. Similar findings were reported in other studies, which observed more diffuse involvement in non-atherosclerotic SCAD [7, 15, 16].

Among patients with early MACE, 62.5% had diffuse dissections (p = 0.027), but the strongest association was between spot lesions and unplanned revascularization (p = 0.005). This highlights the need for further studies investigating how atherosclerosis and lesion type impact outcomes in SCAD.

Patients who required early revascularization were more likely to have initially been followed medically (p = 0.030). Although conservative management is standard for stable SCAD, 5–10% of cases may deteriorate, necessitating intervention [7, 15, 16]. Recent studies show that early major events can still occur under medical therapy [17, 18]. We propose that early revascularization should not be seen as a failure of conservative treatment but as a necessary step for a subset of patients with disease progression.

We found no significant association between common cardiovascular risk factors (e.g., age, diabetes, smoking) and early MACE. However, female sex emerged as a potential predictor of early adverse events (p = 0.001), despite SCAD being more frequent in men in our sample.

Ostial dissections were significantly associated with early MACE (p = 0.006). These lesions may affect larger myocardial areas and increase the risk of infarction. Although some researchers exclude ostial dissections due to the possibility of catheter-induced injury, we included them due to their clinical relevance.

Low pre-treatment EF was another significant predictor of early MACE (p = 0.004), though EF differences diminished during follow-up. This suggests that low baseline EF may be an early risk marker, regardless of later recovery.

Elevated NLR was also associated with early MACE (p = 0.005). NLR is a simple and cost-effective inflammatory marker, and our findings support its potential role in SCAD risk stratification.

Overall, female gender, low EF, high NLR, and ostial dissections may help identify high-risk SCAD patients who need closer monitoring and possibly earlier intervention.

In the longer term, unplanned revascularization occurred in 17 patients and was significantly associated with coronary tortuosity (p = 0.006), a known risk factor for recurrent SCAD [19]. Most of these patients had spot lesions, in contrast to the diffuse patterns seen in early MACE.

Our findings have clinical relevance, particularly for guiding individualized management. While early revascularization did not significantly improve long-term outcomes, the small number of patients limits our ability to assess its efficacy. Although unplanned revascularization was not independently associated with improved long-term outcomes, its occurrence may reflect a subgroup of anatomically high-risk patients experiencing disease progression. This suggests that, in selected cases, earlier intervention based on anatomical predictors such as spot morphology or coronary tortuosity might provide clinical benefit. Future prospective studies with structured follow-up and imaging guidance are warranted to determine whether preemptive revascularization in such patients could improve prognosis. Instead, our aim was to identify predictors of who may eventually require it. Recognizing features like lesion type, tortuosity, and ectasia can help tailor follow-up strategies.

Finally, consistent with the Canadian SCAD cohort, our patients were often discharged on beta-blockers (84.8%) and dual antiplatelet therapy (aspirin in 93.7%, ADP inhibitors in 67.4%) [18]. While beta-blockers are thought to reduce recurrence by lowering wall stress, definitive proof from randomized trials is lacking. Similarly, DAPT is frequently used after PCI, but its role in medically managed SCAD remains unclear.

Compared to the Mayo Clinic SCAD cohort, our clinical presentations were similar. We had a slightly higher rate of STEMI (40.7%) at presentation, consistent with the variable nature of SCAD [14]. However, early MACE and unplanned revascularization were more common in our group. Despite this, long-term outcomes such as MACE and recurrence (~ 25% and ~ 20%, respectively) were comparable [20].

These findings support an individualized approach to SCAD care, guided by lesion characteristics and early clinical markers.

Limitations

The main limitation of this study is the small sample size, due to SCAD being a rare condition and the exclusion of iatrogenic and traumatic cases. Sample size was not calculated a priori due to the retrospective nature of the study and the rarity of SCAD, and therefore the findings should be considered exploratory. Some patients were lost to follow-up, limiting the evaluation of long-term outcomes.

Being a single-center, retrospective study, selection bias is possible. Only patients who presented to our hospital and received a diagnosis were included. Asymptomatic cases or those with atypical symptoms might have been missed.

EF was measured using transthoracic echocardiography, which may vary between observers, especially in retrospective settings.

Revascularization decisions were not blinded and were influenced by clinical and imaging findings at the time. This introduces potential bias.

A significant limitation is the lack of advanced imaging techniques such as IVUS and OCT. These tools could have improved lesion characterization and procedural planning. Future studies using these modalities are needed.

Conclusion

In conclusion, SCAD is a heterogeneous condition that requires individualized management.

Our study identified several predictors of early adverse events: female sex, high NLR, low pre-procedural EF, and ostial dissections. Although initial treatment strategy did not influence early MACE directly, it was associated with increased need for revascularization.

Dissections with plaque tended to cause more severe stenosis. In the mid- to long-term, revascularization was more likely in patients with spot lesions and coronary tortuosity.

These findings emphasize the importance of clinical and anatomical evaluation in guiding treatment and follow-up decisions in SCAD patients.

Although treatment decisions in SCAD are often guided by clinical presentation, our findings suggest that anatomical features—particularly spot lesion morphology and coronary tortuosity—may be more predictive of unplanned revascularization. Patients with these characteristics appear to be at higher risk for requiring intervention in the mid- to long-term period. Notably, none of the patients who underwent CABG required early revascularization, suggesting that surgical revascularization may offer more durable outcomes in select high-risk cases. These findings support the need for a more individualized management strategy in SCAD, where anatomical risk markers are integrated into decision-making and follow-up planning, regardless of the initial treatment approach.

Abbreviations

CABG

Coronary Artery Bypass Grafting

CX

Circumflex Artery

DM

Diabetes Mellitus

EF

Ejection Fraction

IVUS

Intravascular Ultrasound

LAD

Left Anterior Descending Artery

LMCA

Left Main Coronary Artery

MACE

Major Adverse Cardiac Event

MI

Myocardial Infarction

NLR

Neutrophil to Lymphocyte Ratio

NSTEMI

Non ST Elevated Myocardial Infarction

OCT

Optic Coherence Tomography

OR

Odds Ratio

PCI

Percutaneous Coronary Intervention

RCA

Right Coronary Artery

SCAD

Spontaneous Coronary Artery Dissections

STEMI

ST Elevated Myocardial Infarction.

Author contributions

LC, conceptualized and designed the study, led data collection, and supervised project execution. MR, Prepared the initial draft of the manuscript and contributed to data analysis and interpretation.MY, supervised the entire study, guided the research process, and provided critical revisions to the manuscript. TK, Conducted the literature review, contributed to data interpretation, and assisted in manuscript refinement. HEO, Provided methodological insights and contributed to manuscript editing for clarity and coherence.

Funding

This study did not receive any financial support or funding from any sources.

Data availability

The data have not been uploaded to protect the privacy of study participants.

Declarations

Ethics approval and consent to participate

The study protocol was approved by the Dr. Siyami Ersek Thoracic and Cardiovascular Training and Research Hospital’s Ethics Commite (meeting date: 25/12/2020) and the Clinical Research Ethics Committee of Haydarpaşa Numune Training and Research Hospital, Ministry of Health of Turkey (decision number: HNEAH-KAEK 2021/KK/152, date: 17/05/2021). Due to the retrospective nature of the study, informed consent was not obtained from the patients; this waiver was approved by the institutional ethics committees. All patient data included in the study were anonymized prior to analysis to ensure confidentiality. The data were stored in a password-protected digital environment accessible only to the research team and were not shared with any third parties. All procedures were conducted in accordance with the Declaration of Helsinki and relevant local ethical regulations.

Consent for publication

We hereby declare our consent for the publication of this study.

Competing interests

The authors declare no competing interests.