Invasive Management of Acute Myocardial Infarctions During the Initial Wave of the COVID-19 Pandemic

Abstract

Background:

The initial wave of the coronavirus disease 2019 (COVID-19) pandemic resulted in an influx of patients with acute viral illness and profound changes in healthcare delivery in New York City. The impact of this pandemic on the presentation and invasive management of acute myocardial infarction (MI) is not well described.

Methods:

This single-center retrospective study compared patients with MI who underwent invasive coronary angiography at NYU in March-April 2020, during the peak of the first wave of the pandemic, to those presenting in March-April 2019.

Results:

Only 35 patients with MI underwent angiography during the study period in 2020 versus 109 in 2019. No differences in comorbidities or baseline medications were identified. The proportion of patients with ST segment elevation MI (STEMI) was higher in 2020 (48.6% vs. 24.8% in 2019, p = 0.014). Median peak troponin concentration was higher (14.5 vs. 2.9 ng/mL, p = 0.005) and left ventricular ejection fraction was lower (43.34% vs. 51.1%, p = 0.015) during the pandemic. Among patients with non-STEMI, time from symptom onset to presentation was delayed in 2020 compared to 2019 (median 24 hours versus 10 hours, p = 0.04).

Conclusion:

There was a dramatic decrease in the number of patients with MI undergoing coronary angiography during the first wave of the COVID-19 pandemic. Of those that presented, patients tended to seek care later after symptom onset and had excess myocardial injury. These data indicate a need for improved patient education to ensure timely cardiovascular care during public health emergencies.

Background:

The coronavirus disease 2019 (COVID-19) pandemic has resulted in excess morbidity and mortality nationwide ¹. During the initial wave of the pandemic in New York City, healthcare systems were overwhelmed by a sudden influx of patients presenting with COVID-19 related illness. At the same time, a surge in the number of out-of-hospital cardiac arrests was reported. ². The impact of COVID-19 on the invasive management of acute coronary syndromes has not been fully characterized. Prior series have reported decreased volumes of ST segment myocardial infarctions (STEMI), but most studies did not evaluate the impact on non-ST segment myocardial infarction (NSTEMI) ^3–12. We assessed the volume, clinical characteristics, and in-hospital outcomes of patients with myocardial infarction (MI) referred for invasive management at a large tertiary care hospital during the initial 2 months of the pandemic compared to the same 2-month period one year prior to the COVID-19 pandemic.

Methods:

We conducted a single-center retrospective analysis of patients presenting to the New York University Langone Health: Manhattan Campus with acute MI who were referred for urgent or emergent invasive coronary angiography during the initial wave of the COVID-19 pandemic, from March 1, 2020 to April 30, 2020, compared to the same time period in the prior year (March 1, 2019 to April 30, 2019).

Myocardial infarction was defined according to the Universal Definition of MI based on clinical evidence of ischemia and an elevated troponin value above the 99th percentile upper reference limit (URL), as determined retrospectively from medical record review ¹³. STEMI was defined by new ST-segment elevations >1mm in two contiguous leads or a new left bundle branch block on ECG.

Electronic health records were reviewed for demographics, clinical comorbidities, characteristics of the MI presentation, relevant laboratory data, and the results of cardiovascular testing, including echocardiography and invasive coronary angiography. Hospital length of stay, the need for critical care services, and all-cause in-hospital mortality were determined for all patients. Among patients who underwent multiple coronary angiograms during the study time period, only the first encounter for MI was included in the analysis.

Statistical Analysis:

Categorical data were summarized using frequency and percent and were compared by Pearson’s chi-square test with continuity correction. Normally distributed continuous variables were reported as mean ± standard deviation and were compared using independent samples t-tests. All other continuous data were reported with median and interquartile range (IQR) and compared using the Kruskal-Wallis test. The Shapiro-Wilk test was used to assess for normality. Statistical significance was assessed at 0.05. Data were analyzed using R Software R 3.5.2 (Vienna, Austria). The New York University School of Medicine institutional review board approved the study and granted a waiver of written informed consent.

Results:

A total of 144 patients with STEMI or non-STEMI were referred for urgent or emergent invasive coronary angiography during the specified time periods in 2019 and 2020. We observed a 68% decrease in MI presentations during the COVID-19 pandemic compared to the prior year (35 MI patients in 2020 versus 109 in 2019, p<0.001).

Overall, the median age of MI patients in both time periods was 64 +/− 15 years and 31.9% were women. Hypertension (68.1%) and diabetes mellitus (34.7%) were common among patients presenting with MI. A prior MI was reported in 29.9% of patients. There were no significant differences in baseline characteristics or comorbidities between the two study time periods (Table 1). Four patients (11.4%) who underwent invasive management of MI in 2020 had a detectable polymerase chain reaction assay for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

Table 1:

Demographics and baseline comorbidities of patients undergoing invasive coronary angiography for acute myocardial infarction in 2020 versus 2019.

Characteristics	COVID-era (2020) N = 35	Pre-COVID (2019) N = 109	P-value
Age, mean (SD)	62 (15.32)	65 (15.26)	0.422
Male Sex, n (%)	24 (70.6%)	72 (67.3%)	0.882
Race/Ethnicity, n (%)			0.033
White (non-Hispanic)	16 (45.7%)	79 (72.5%)
African American	3 (8.6%)	3 (2.8%)
Asian	6 (17.1%)	7 (6.4%)
Hispanic	5 (14.3%)	13 (11.9%)
Other/Unknown	5 (14.3%)	7 (6.4%)
Body Mass Index, mean (SD)	28.29 (7.94)	28.92 (5.25)	0.603
Hypertension, n (%)	23 (65.7%)	75 (68.8%)	0.894
Diabetes Mellitus, n (%)	14 (40%)	36 (33%)	0.582
Heart Failure, n (%)	6 (17.1%)	23 (21.1%)	0.190
Asthma, n (%)	3 (8.6%)	6 (5.5%)	0.802
COPD, n (%)	3 (8.6%)	8 (7.3%)	1.000
Prior DVT/PE, n (%)	3 (8.6%)	3 (2.8%)	0.311
Prior Stroke, n (%)	3 (8.6%)	10 (9.2%)	1.000
Prior MI, n (%)	10 (28.6%)	33 (30.3%)	0.208
Chronic Kidney Disease, n (%)	3 (8.6%)	18 (16.5%)	0.377
Malignancy, n (%)	5 (14.3%)	11 (10.1%)	0.706
Tobacco use, n (%)	17 (48.6%)	40 (36.7 %)	0.293
Alcohol Use, n (%)	7 (20.0%)	40 (36.7%)	0.104

The proportion of patients presenting with STEMI increased from 24.8% in 2019 to 48.6% during the COVID-19 pandemic in 2020 (p = 0.014). There were longer delays between reported MI symptom onset and emergency department arrival in 2020 compared to 2019 in patients with NSTEMI (median 24 hours versus 10 hours, p=0.037). Although the time from symptom onset to presentation in patients with STEMI was also numerically greater in 2020 compared to 2019, this difference was not significant (median 6 hours in 2020 versus 1.5 hours in 2019, p =0.42).

Vital signs at hospital presentation did not vary between the two time periods (Table 2). While no difference in initial troponin concentration was observed, median peak troponin concentration (14.48 vs. 2.94 ng/mL, p = 0.005) and aspartate transaminase level (39 vs. 24 units/L, p = 0.008) were significantly higher in 2020 versus 2019. There were no significant differences in other laboratory parameters between the two time periods (Table 2). Mean left ventricular ejection fraction by echocardiography was lower in 2020 compared to 2019 (43.34% vs. 51.10%, p = 0.015).

Table 2:

Vital signs and laboratory values at hospital presentation among patients with acute myocardial infarction undergoing invasive coroanry angiography in 2020 versus 2019.

Characteristics	COVID-era (2020) N = 35	Pre-COVID (2019) N = 109	P-value
Vital Signs:
Systolic Blood Pressure, mean (SD)	131.06 (27.92)	139.01 (25.05)	0.115
Diastolic Blood Pressure, mean (SD)	82.54 (19.94)	83.05 (21.08)	0.900
Heart Rate, mean (SD)	86.60 (24.56)	83.93 (21.46)	0.540
Temperature, mean (SD)	37.07 (0.76)	39.25 (11.90)	0.296
Oxygen Saturation (%), median [IQR]	95 [94,98]	97 [94,98]	0.326
Troponin – Admission, median [IQR]	0.38 [0.08, 2.96]	0.16 [0.04, 1.22]	0.204
Troponin – Peak, median [IQR]	14.48 [0.67, 101.61]	2.94 [0.25, 18.60]	0.005
Complete Blood Count:
WBC, median [IQR]	9.70 [7.90, 11.90]	9.30 [7.10, 11.85]	0.332
Absolute Lymphocyte Count, median [IQR]	1.45 [1.00, 2.38]	1.60 [1.20, 2.40]	0.385
Hemoglobin, median [IQR]	14.2 [12.2, 15.15]	13.4 [11.95, 14.70]	0.373
Platelet Count, median [IQR]	223 [165, 275]	226 [179, 281.25]	0.483
Metabolic Panel:
Na, median [IQR]	140 [137.5, 142]	138 [136, 140]	0.003
K, median [IQR]	4.20 [3.85, 4.45]	4.10 [3.80, 4.50]	0.355
CO2, median [IQR]	22.00 [20.50, 24.00]	24 [21.00, 26.00]	0.109
Cr, median [IQR]	1.14 [0.90, 1.56]	0.98 [0.83, 1.23]	0.109
AST, median [IQR]	39.00 [27.00, 88.00]	24.00 [18.00, 47.25]	0.008
Total Bilirubin, median [IQR]	0.80 [0.50, 1.00]	0.60 [0.40, 0.92]	0.119
Albumin, median [IQR]	3.80 [3.60, 4.10]	4.05 [3.77, 4.20]	0.036
SARS-CoV-2 Detected by PCR, n (%)	4 (11.4%)	N/A	N/A

Results of coronary angiography are shown in Table 3. The proportion of patients that had MI with non-obstructive coronaries did not differ between 2020 and 2019 (12.5% versus 14.8%) (Table 3). A lower proportion of patients had multi-vessel disease in 2020 compared to 2019 (31.4% versus 64.2%, p = 0.001); single vessel coronary artery disease was present in 53.1% of patients in 2020 and only 20.4% of patients in 2019. The MI culprit vessel was most frequently the left anterior descending artery (30.6% of cases), followed by the right coronary (23.6% of cases) and left circumflex (17.4% of cases) arteries. Overall, PCI was performed in 63.9% of patients who underwent invasive coronary angiography for MI, with no difference between the two time periods. Among patients with STEMI, the median door to balloon time was increased in 2020 compared to in 2019 (1.14 hours versus 0.76 hours, p = 0.023).

Table 3:

Results of cardiovascular testing, management of MI, and outcomes among patients with acute myocardial infarction undergoing invasive coroanry angiography in 2020 versus 2019.

Characteristics	COVID-era (2020) N = 35	Pre-COVID (2019) N = 109	P-value
STEMI, N (%)	17 (48.6)	27 (24.8)	0.014
Time between symptom onset and ED presentation in hours, median [IQR]
All Patients	24 [6, 96]	6.5 [2, 54]	0.135
STEMI Patients	6 [1, 24]	1.5 [1, 24]	0.415
Non-STEMI Patients	24 [21, 102]	10 [3, 72]	0.037
CAD Severity at Coronary Angiography, n (%)			0.002
No Obstructive CAD	4 (11.4)	16 (14.7)
1-vessel CAD	17 (48.6)	22 (20.2)
2-vessel CAD	6 (17.1)	25 (22.9)
3-vessel CAD	5 (14.3)	45 (41.3)
Multivessel Disease	11 (31.4)	70 (64.2)	0.001
PCI Performed	24 (68.6)	68 (62.4)	0.378
Number of Stents Placed	1.07 (0.86)	1.15 (1.06)	0.709
Aspiration Thrombectomy, n (%)	12 (34.3)	20 (18.3)	0.082
Door to Balloon Time, in hours (STEMI only), median [IQR]	1.14 [0.93, 1.69]	0.76 [0.62, 1.08]	0.023
Culprit Vessel
Left Main,, n (%)	3 (8.6)	9 (8.3)	1.000
LAD, n (%)	12 (34.3)	32 (29.4)	0.734
Diagonal, n (%)	1 (2.9)	14 (87.2)	0.172
Circumflex, n (%)	10 (28.6)	15 (13.8)	0.079
Obtuse Marginal, n (%)	1 (2.9)	8 (7.3)	0.581
RCA, n (%)	4 (11.4)	30 (27.5)	0.085
PDA, n (%)	0 (0)	1 (0.9)	1.000
LV Ejection Fraction by Echocardiography, mean (SD)	43 (17.70)	51 (14.75)	0.015
Moderate-Severe Valve Disease by Echocardiography, n (%)	8 (22.9)	19 (17.4)	0.651
Hemodynamic Support Required (Any), n (%)	6 (17.1)	17 (15.6)	0.828
Vasopressors / Inotropes	4 (11.4)	9 (8.3)
Intra-Aortic Balloon Pump (IABP)	2 (5.7)	6 (5.5)
Percutaneous LVAD / Impella	0 (0)	1 (0.9)
Extracorporeal Membrane Oxygenation (ECMO)	0 (0)	1 (0.9)
Cardiac Arrest	6 (17.1)	5 (4.6)	0.039
Pre-Procedure	4 (11.4)	3 (2.8)
Peri-Procedure	2 (5.7)	2 (1.8)
Hospital Length of Stay in days, median [IQR]	3 [2, 6.75]	3 [2, 6]	0.566
ICU Level of Care, n (%)	16 (45.7)	47 (43.1)	0.941
In-hospital Mortality, n (%)	6 (17.1)	7 (6.4)	0.113

Procedural aspects of percutaneous coronary intervention are shown in Table 3. Among individuals undergoing PCI, the mean number of coronary stents implanted was 1.13±1.01. A numerically higher proportion of patients underwent aspiration thrombectomy in 2020 compared to 2019 (34.3% versus 18.3%, p = 0.08). None of the patients in 2020 received glycoprotein IIb/IIIa inhibitors, and only 2 patients received these agents in 2019. Coronary thrombolysis with tissue plasminogen activator was not administered to any MI patients in 2020 and only 1 patient received this therapy in 2019. None of the patients in either time period developed mechanical complications of MI. Overall, 16% of patients required hemodynamic support with inotropes/pressors or mechanical circulatory support devices, with no differences between 2020 and 2019 (Table 3).

The median inpatient length of stay was 3 days in both time periods. There was no difference in the proportion of patients requiring treatment in an intensive care unit (ICU) (45.7% in 2020 versus 43.1% in 2019, p=0.941). A greater proportion of patients had cardiac arrest in 2020 compared to in 2019 (17.1% versus 4.6%, p = 0.039). There was numerically higher in-hospital mortality in 2020 compared to 2019 (17.1% versus 6.4%, p=0.11). Three of the 4 patients with COVID-19 and MI required ICU care and 1 died in-hospital.

Discussion:

In this retrospective review of patients with MI who were referred for urgent or emergent invasive coronary angiography during the peak of the initial wave of the COVID-19 pandemic, compared to the same time period in the previous year, we found (1) a dramatic decrease in patient volume, (2) an increase in the proportion of STEMI versus non-STEMI cases, (3) a delay in the time from symptom onset to presentation and to intervention, and (4) greater myocardial injury, as evidenced by higher peak troponin concentration and reduced left ventricular ejection fraction. We also observed a trend toward increased in-hospital mortality among patients with MI during the initial wave of the COVID-19 pandemic.

New York City healthcare systems were inundated and overwhelmed with COVID-19 patients in the initial wave of the pandemic ⁶. Despite this, we observed a decline in the volume of patients presenting with STEMI and non-STEMI who underwent invasive management. These data are consistent with previously reported observations of fewer MI presentations across the US and around the world ^{3, 5, 7–12, 14}, and reductions in hospital presentations for reasons other than SARS-CoV-2 infection during the initial wave of the COVID-19 pandemic ¹⁵. Although fewer STEMI and NSTEMI presentations during the COVID-19 pandemic were previously reported in a series from Upstate New York, our study is the first to report excess myocardial injury associated with delays in hospital presentation ¹⁴.

The profound decline in hospital presentations with invasive management of MI is somewhat perplexing, since thrombosis is a prominent clinical feature of severe COVID-19 ^{16, 17}. COVID-19 has also been reported to cause acute decompensated heart failure exacerbations, cardiogenic shock, tachyarrhythmias, myocarditis and Takotsubo syndrome ^{18, 19}, and the clinical presentation of many of these entities may mimic acute MI ⁴. Furthermore, events associated with high emotional stress have historically been associated with excess risk of MI ²⁰. The first few months of the COVID-19 pandemic included a state of emergency declaration by the New York governor’s office on March 7, 2020, a long period of uncertainty regarding disease transmission, and economic and social implications of the statewide stay-at-home order. These events may have conferred significant emotional stress to New Yorkers during this time period.

The cause of the steep decline in MI presentations during the initial wave of COVID-19 in New York remains uncertain ^{11, 14}. Fewer patients may have been willing to leave their homes for symptoms of MI due to the statewide stay-at-home order and public health messaging focusing on staying home during the initial weeks of the pandemic to avoid over-burdening the health system. The sedentary lifestyle encouraged by public health authorities during this time period may have provided fewer opportunities for exercise-induced, sheer-stress mediated acute coronary plaque ruptures. In addition, fewer commuters entering New York City and relocation of city residents to suburban or rural dwellings may have decreased the population at-risk during the early stages of the pandemic COVID-19. A large driver of the decreased volume of MI presentations undergoing invasive coronary angiography may also have been due to patient fear of SARS-CoV-2 transmission and COVID-19 ¹⁹. Finally, early guidance from cardiovascular societies recommended medical management of patients with low risk non-STEMI and probable COVID-19, which may have impacted referrals for invasive management of MI at our institution

We also observed a change in the nature of acute MI cases that presented to the hospital for evaluation. A greater proportion of patients with acute MI presented with STEMI, and a higher proportion of patients had single-vessel disease, compared to patients presenting the previous year. We observed higher peak cardiac biomarkers and lower left ventricular ejection fractions by echocardiography, indicative of increased extent of myocardial injury in patients presenting during the peak of the pandemic. This may have been due to delayed times from symptom onset to hospital presentation during the initial wave of the pandemic. No differences in the need for hemodynamic or mechanical circulatory support were observed between groups.

Despite the decrease in the numbers of patients presenting with acute MI, epidemiologic data indicate excess all-cause mortality in early 2020 compared to previous years ¹. Notably, there was a substantial increase in out-of-hospital cardiac arrests during the peak of the pandemic, compared to during the previous year ². These data perhaps suggest that greater numbers of patients with MI stayed at home, rather than presenting to the hospital for inpatient care; this may have lead to excess out-of-hospital MI-associated fatalities. Surprisingly, few patents in our cohort had PCR-detected SARS-CoV-2, despite the fact that myocardial injury is common in COVID-19 and is a poor prognostic indicator ^{6, 21–23}. Our observation that greater myocardial injury occurred during the pandemic is perhaps less likely due to concomitant COVID-19, and more likely related to delays in patient presentation with MI. However, these findings may also be confounded by low testing rates in the initial wave of the pandemic.

Our findings offer a sobering assessment of the public health messaging conveyed during the initial wave of the pandemic. Fear of overwhelming hospital systems and efforts to institute a city-wide lockdown may have dissuaded patients from seeking urgent and necessary cardiovascular care. This may have also led to significant delays in cancer diagnoses and treatment during the pandemic ^{24, 25}. Ultimately, the dramatic decrease in the number of patients presenting to the cardiac catheterization laboratory with acute MI and the delayed time to presentation during the peak of the pandemic indicate the need for improved public health messaging to ensure timely and appropriate cardiovascular care. Public education regarding measures to provide safe access to healthcare during future emergencies are warranted.

Limitations:

Our results should be interpreted within the context of several limitations. This was a retrospective, cross-sectional, single-center observational study, and we were unable to make causal associations regarding changes in MI volume and clinical characteristics over time. As we required an elevated troponin in our criteria for study inclusion, we did not include cases of unstable angina. COVID-19 tests were not widely available during the initial weeks of the pandemic, limiting our ability to infer associations between SARS-CoV-2 status and MI presentation and outcomes. Patients who were managed medically and were not referred for invasive coronary angiography were not included in this analysis. Early guidance from cardiovascular societies recommended weighing exposure risks against revascularization benefits, and patients with COVID-19-associated MI may not have undergone revascularization due to concerns regarding comorbid respiratory illness and the competing risks of death ²⁶.

Conclusions:

We observed a decrease in patients with MI undergoing invasive coronary angiography during the first wave of the COVID-19 pandemic. Patients who did present for care during the pandemic tended to arrive later, were more likely to have STEMI, and had higher peak troponin concentrations and decreased ejection fractions. Our findings demonstrate the need to improve public health messaging to ensure timely and appropriate cardiovascular care. Future public health efforts should focus on providing safe access to healthcare, especially in disasters.

Figure Legend:

We noted a significant reduction (68%) in patients with acute myocardial infarction referred for coronary angiography during the peak of the pandemic, compared to during the previous year. Of the patients referred for angiography, a greater proportion had STEMI compared to during the previous year.