Treatment charges for acute coronary syndrome: A retrospective analysis

Abstract

Background

This study analyzes the costs associated with treatment strategies for acute coronary syndrome: coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), and medical management (MM).

Methods

This is a substudy of a previous analysis showing improved outcomes with CABG compared to PCI and MM, now focusing on variation in charges based on the type of treatment, hospital length of stay (LOS), and the occurrence of hospital readmission. We extracted total reimbursements, LOS, and readmissions for acute coronary syndrome patients (4267) between 2018 and 2022 from the electronic health record.

Results

Expenses related to total charges were higher for CABG patients than PCI patients (+$106,047); however, average daily charges were lower for CABG patients compared to PCI patients (+$14,957). LOS was a primary driver for total charges, as CABG patients stayed 8.35 ± 0.50 days longer than PCI patients on average. The average difference between the total charge amount for readmitted and nonreadmitted patients was $22,765 ± $11,820. Even though readmission increases total charges, the charge per day was still less in patients with readmission due to their longer LOS.

Conclusion

The higher total charge amount and lower charge per day in CABG patients compared to PCI patients, as well as readmitted patients, highlights the importance of employing strategies to reduce LOS and minimize charges for CABG and readmissions.

Acute coronary syndrome (ACS) is the leading cause of mortality and morbidity throughout the world and is increasing in proportion due to an aging population with confounded comorbidities such as hypertension and diabetes.¹ Due to the global impact in addition to the high cost of care for patients with ACS, recent efforts have focused on finding ways to reduce the financial impact of care for patients with ACS.

Some of the most utilized treatments for ACS include coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI). Both of these procedures provide revascularization to areas that were ischemic secondary to obstructive atherosclerotic lesions. The CABG procedure involves grafting a healthy vessel from part of the body and using this vessel to bypass a blocked coronary artery.² This procedure has been associated with higher postoperative infection rates, a longer length of stay (LOS), and greater risk of complications after surgery when compared to PCI, but with fewer hard outcomes such as death and cardiovascular events.³ A PCI involves placing a stent in a narrowed vessel to dilate it. This procedure is less invasive, shortens recovery times, and reduces the risk of complications compared to CABG.⁴

This paper aimed to examine the differences in total charges, LOS, and readmissions among patients receiving care for ACS based on receiving medical management (MM), PCI, and CABG within a large heterogenous healthcare system in Texas, with the hypothesis that charges for PCI would be less than charges for CABG. Furthermore, we studied causes for the increased cost among the various revascularization methods.

METHODS

This study was a retrospective analysis of the charge amount for treatment of patients diagnosed with ACS. A total of 4267 patients ranging from 21 to 107 years old with an ACS diagnosis were selected from 2018 to 2022 across eight sites in a large healthcare system in Texas. The protocol and outcomes have been previously reported. The patients were first divided into groups by the treatment type received: CABG, PCI, or MM. Patients were also further divided into subgroups based on readmission status—defined as a rehospitalization postrevascularization within 30 days of discharge.

The raw data obtained for each patient included the total charge amount, total payment amount, hospital LOS, and presence of hospital readmission. We then abstracted a total cost amount on a per-patient basis. An average of these raw numbers was calculated and recorded using Microsoft Excel. Also, from this data, we calculated the average charge per day, payment per day, and direct cost per day. Medians and interquartile ranges (IQR) were reported for each of these figures, as well as means and standard deviations (SD). Patients who did not use insurance and reported “self-pay” did not report their total payment amount and were therefore excluded from this category and the payment per day category (<5% of the total cohort). Also, 61 patients did not have their designated choice of treatment recorded, so these patients were left out of all calculations.

We calculated means and standard deviations across each treatment group using the program Prism 10 (GraphPad, Boston, MA). We then assessed between-group differences using ANOVA testing. Figures 2 and 3 were created using Brown-Forsythe and Welch ANOVA tests, which compare three or more independent groups, assuming normal distribution, but without requiring equal variances across said groups. For each of these graphs, different treatment groups and associated changes were compared to see if there was statistical significance among the different groups. We used a predetermined significance level of <0.05.

Figure 2.

Trends across treatment groups for (a) total charge amount, (b) charge per day, and (c) length of stay (LOS). (a) The total charge amount was highest in CABG ($276,156), followed by PCI ($128,479) and MM ($80,269). The differences in total charge amount were significant between CABG and PCI, and CABG and MM (P < 0.01). (b) Charge per day amount was highest in PCI ($38,701), followed by CABG ($21,724) and MM ($12,939). The charge per day amount differences were significant across all three comparisons (P < 0.01). (c) LOS was the longest in CABG (12.79), followed by MM (8.97) and PCI (6.07). The differences in LOS were significant across all three comparisons (P < 0.01). CABG indicates coronary artery bypass grafting; MM, medical management; PCI, percutaneous coronary intervention.

Figure 3.

Trends in charge per day amount across treatment subgroups stratified by the presence or absence of a 30-day readmission. The charge per day amount was highest in PCI patients without a readmission ($35,517) and lowest in MM patients with a readmission ($12,098). Notably, the differences in charges were not significant when comparing readmitted to not readmitted patients within each treatment group. CABG indicates coronary artery bypass grafting; MM, medical management; PCI, percutaneous coronary intervention.

RESULTS

The baseline demographics of the cohorts are summarized in Table 1. Patients who received CABG were younger (median age 67 years; IQR = 60, 74) compared to those in the PCI (69 years; IQR = 60, 77) and MM (72 years; IQR = 61, 83) cohorts. The proportion of females was highest in the MM cohort (49.04%) and lowest in the CABG cohort (26.05%). Racial distribution was relatively consistent across cohorts, except for a higher proportion of Black or African American patients in the MM cohort compared to other races. Ethnic representation also showed relative consistency across cohorts, with Hispanic or Latino patients comprising 13.12%, 15.43%, and 12.65% in the PCI, CABG, and MM cohorts, respectively.

Table 1.

Demographic characteristics of patients undergoing PCI, CABG, and medical management for acute coronary syndrome

Variable	Category	PCI (N = 1197)	CABG (N = 311)	MM (N = 2759)
Age (yr): Median (IQR)		69 (17)	67 (14)	72 (22)
Gender	Female	416 (34.75%)	81 (26.05%)	1353 (49.04%)
	Male	780 (65.16%)	230 (73.95%)	1406 (50.96%)
	Unknown	1 (0.08%)	0 (0%)	0 (0%)
Race	White	1028 (85.88%)	260 (83.6%)	2118 (76.77%)
	Black or African American	114 (9.52%)	28 (9%)	515 (18.67%)
	Asian	13 (1.09%)	5 (1.61%)	25 (0.91%)
	American Indian or Alaskan Native	6 (0.5%)	1 (0.32%)	11 (0.4%)
	Native Hawaiian or other Pacific Islander	0 (0%)	4 (1.29%)	11 (0.4%)
	Other race	17 (1.42%)	10 (3.22%)	58 (2.1%)
	Unknown	19 (1.59%)	3 (0.96%)	21 (0.76%)
Ethnic group	Hispanic or Latino	157 (13.12%)	48 (15.43%)	349 (12.65%)
	Not Hispanic or Latino	1026 (85.71%)	260 (83.6%)	2391 (86.66%)
	Unknown	14 (1.17%)	3 (0.96%)	19 (0.69%)

CABG indicates coronary artery bypass grafting; IQR, interquartile range; MM, medical management; PCI, percutaneous coronary intervention.

Tables 2 and 3 and Figures 2 and 3 provide the data found in the charge analysis of ACS treatments. An important finding is that CABG cost significantly more than PCI when looking at the total charge amount, with CABG charging $199,712 (± $99,014) and PCI charging $93,665 (± $51,835) on average (P < 0.01). Notably, CABG patients were charged significantly less than PCI patients on a per-day basis, at $19,755 (± $8,090) compared to $34,712 (± $20,613), respectively (P < 0.01). When comparing these groups, CABG had a longer average LOS at 12.79 (± 8.29) than PCI, with an average LOS of 4.45 (± 6.07; P < 0.01).

Table 2.

Total expenses, length of stay, and charge-related metrics for patients undergoing PCI, CABG, and medical management for acute coronary syndrome, stratified by readmission status (medians and interquartile ranges)

Group	Sample size	Total charged median	IQR of total charged	Total payment median	Total direct cost median	Average stay	SD of average stay	Charge per day median	IQR of charge per day	Payment per day median	Direct cost per day median
PCI	1197	$93,665	$51,835	$22,074		4.45	± 6.07	$34,712	$20,613	$7738
Readmitted PCI	32	$114,199	$105,787	$22,694	$10,227	8.06	± 7.89	$19,112	$25,113	$3551	$2109
Not readmitted PCI	1316	$89,102	$48,981	$20,200		4.45	± 5.93	$32,506	$22,657	$7272
CABG	311	$199,712	$99,014	$52,507		8.30	± 12.81	$19,755	$8090	$5089
Readmitted CABG	19	$202,712	$146,145	$47,192	$31,310	14.47	± 12.19	$20,662	$14,949	$4920	$3622
Not readmitted CABG	297	$184,362	$98,005	$47,610		11.84	± 8.11	$19,076	$7699	$5074
MM	2759	$43,159	$57,349	$11,950		6.88	± 8.97	$10,150	$7614	$2637
Readmitted MM	95	$66,567	$89,503	$14,668	$9290	9.93	± 10.24	$10,596	$6066	$2527	$1438
Not readmitted MM	2630	$42,605	$56,479	$11,851		6.75	± 8.81	$10,137	$7736	$2639
Readmission	145	$91,514	$141,509	$39,051	$10,675	9.94	± 9.98	$11,974	$9851	$2960	$2283
No readmission	4305	$68,748	$83,761	$14,875		6.72	± 8.57	$14,346	$19,167	$3574

CABG indicates coronary artery bypass grafting; IQR, interquartile range; MM, medical management; PCI, percutaneous coronary intervention; SD, standard deviation.

Table 3.

Total expenses, length of stay, and charge-related metrics for patients undergoing PCI, CABG, and medical management for acute coronary syndrome, stratified by readmission status (means and standard deviations)

Group	Sample size	Total charged	SD of total charged	Total payment	Total direct cost	Average stay	SD of average stay	Charged per day	SD of charged per day	Payment per day	SD of payment per day	Direct cost per day	SD of direct cost per day
PCI	1197	$128,379	± $145,847	$31,968		4.45	± 6.07	$38,701	± $22,255	$10,048	± $11,148
Readmitted PCI	32	$168,075	± $212,767	$41,302	$23,134	8.06	± 7.89	$27,835	± $25,694	$8830	± $17,211	$2849	± $2839
Not readmitted PCI	1316	$117,287	± $135,788	$29,055		4.45	± 5.93	$35,517	± $22,956	$9238	± $10,571
CABG	311	$276,156	± $273,941	$78,759		12.79	± 8.29	$21,724	± $9449	$6584	± $4683
Readmitted CABG	19	$347,100	± $395,721	$81,931	$62,071	14.47	± 12.19	$22,239	± $7864	$5033	± $1890	$3622	± $1544
Not readmitted CABG	297	$234,137	± $211,649	$69,711		11.84	± 8.11	$20,090	± $9426	$6322	± $4860
MM	2759	$80,269	± $146,689	$22,323		6.88	± 8.97	$12,939	± $12,029	$3809	± $6347
Readmitted MM	95	$124,297	± $183,984	$31,803	$22,772	9.93	± 10.24	$12,098	± $6198	$3334	± $3433	$1876	± $1445
Not readmitted MM	2630	$78,556	± $144,874	$22,072		6.75	± 8.81	$13,004	± $12,251	$3839	± $6465
Readmission	145	$155,589	± $221,480	$39,051	$26,419	9.94	± 9.98	$16,743	± $14,772	$4738	± $8767	$2283	± $1909
No readmission	4305	$101,204	± $152,589	$27,516		6.72	± 8.57	$20,483	± $19,167	$5663	± $8246

CABG indicates coronary artery bypass grafting; IQR, interquartile range; MM, medical management; PCI, percutaneous coronary intervention; SD, standard deviation.

Patients who experienced a readmission were charged $22,765 (±$11,820) more on average than those who did not experience a readmission. These readmitted patients also spent 3.22 (± 0.83) more days in the hospital than patients without a readmission on average.

DISCUSSION

The main conclusion from these data is that the relationship between ACS interventions appears the same as previously described for a diverse population served by a large integrated delivery network in a diverse and growing state with a large risk burden for CAD. Reducing inpatient LOS is one potential way to reduce the impact on resource utilization in the care for ACS patients, and additional measures should also be investigated and explored.

The data obtained revealed substantial variability in the total charge amount, charge per day, and hospital LOS for the different ACS treatment modalities. For example, CABG had a notably higher total charge when compared to PCI and MM, which highlights CABG as a target for cost-containment strategies—especially in light of the relative short- and long-term cardiovascular outcome benefits in patients with multivessel ACS. Some of the other important findings to note are that MM patients had the least total charge amount, charge per day amount, and LOS. Additionally, patients who were readmitted incurred significantly higher total charges than those without a readmission, with median charges of $91,514 versus $68,748. This cost difference aligns with their longer average LOS, which was 9.9 days compared to 6.7 days (approximately a 3:2 ratio).

The high standard deviation in charges across treatment types indicates that costs are not consistent, which could suggest variations in practice patterns, resource utilization, or patient severity within each group. Addressing these inconsistencies might help standardize costs.

According to a review of prospective randomized trials comparing CABG to PCI, CABG has lower overall mortality as well as a reduction in nonlethal myocardial infarction and cardiac death.² The total amount patients are charged for treatment of their ACS is directly correlated to the hospital LOS (Figure 1). This highlights the importance of minimizing LOS as a means of reducing the cost of treatment and therefore reducing the amount patients are charged. This is especially important in CABG patients, as their total charge amount is much higher than that of PCI patients, despite CABG patients having a lower charge per day due to their longer LOS.⁵

Figure 1.

The total charge amount for individual patients from the entire data set based on their length of stay (LOS). The trend line is y = 14,432x + 9,549.1, and the coefficient of determination is reported as R^` = 0.5917.

The data collected on the charge analysis of ACS are supported by similar studies conducted in the past. Compared to two studies that broke down the difference in cost between PCI and CABG, our data also found that CABG costs significantly more than PCI. These studies also found, though, that CABG was more cost-effective over a 5-year period compared to PCI,⁶ and CABG was the favored cost-effective treatment for complex multivessel coronary artery disease in the long term (2–5 years) due to the cost of revascularization from restenosis following PCI.⁷

There was no randomization in treatment allocations based on the condition of the patient, age of the patient, and comorbidities, therefore introducing a selection bias. The patient’s management was at the discretion of the attending physician rather than being randomly assigned. For instance, a patient with multivessel coronary artery disease may benefit more from CABG, whereas a healthier individual may undergo PCI or MM, which could predispose the CABG patients to an unavoidable increased LOS. Age could have also made a difference in care, leaning older patients toward PCI, as CABG is less suitable for them. The nonrandomization of patient care could lead to differences in outcomes and cost efficiency. Some of the results of this study could partially be explained by these underlying factors rather than the treatment modalities themselves. This could limit the ability to draw definitive conclusions from this analysis.

In conclusion, the higher total charge amount and LOS for CABG when compared to PCI supports an argument for employing strategies to minimize cost and reduce LOS for CABG patients. These strategies should include optimizing preoperative assessment, streamlining intraoperative efficiency, and having a focused postoperative care plan to minimize inpatient time. Ensuring patients are in optimal condition before surgery via appropriately managing conditions such as diabetes or anemia can speed up the process of inpatient care.⁸

Funding Statement

Central Texas Foundation, Baylor Scott and White

Disclosure statement/Funding

The authors gratefully acknowledge funding support from the Cardiovascular Research Review Committee at Baylor Scott & White Research Institute. Dr. Widmer declares industry relationships with Philips, Medtronic, and Abbott. The other authors report no potential conflicts of interest.