Acute coronary syndrome (ACS), a spectrum of conditions associated with sudden reduced blood flow to the heart, is a major cause of morbidity and mortality worldwide. Chronic obstructive pulmonary disease (COPD), a progressive lung disease characterized by airflow limitation, frequently coexists with cardiovascular disorders, especially ischemic heart disease, due to shared risk factors such as smoking, systemic inflammation, and aging [1]. The coexistence of COPD in patients with ACS complicates diagnosis, management, and prognosis, making early and accurate assessment crucial.

Echocardiography remains a cornerstone in evaluating cardiac function in ACS patients. It provides essential information on left ventricular systolic and diastolic function, wall motion abnormalities, ejection fraction (EF), and pulmonary artery pressures [2]. However, in COPD patients, hyperinflation of the lungs and altered thoracic anatomy may impede acoustic windows, potentially reducing image quality and limiting interpretation [3]. Moreover, COPD-related right heart strain can mimic or mask echocardiographic signs of myocardial ischemia, complicating clinical decisions [4].

Several echocardiographic parameters such as reduced left ventricular EF, elevated pulmonary artery systolic pressure (PASP), and right ventricular dysfunction are common findings in COPD-ACS overlap patients [5]. Tissue Doppler imaging and speckle-tracking echocardiography have been increasingly utilized to overcome some of these challenges, offering enhanced sensitivity in detecting subclinical dysfunction [6].

Understanding the interplay between COPD and ACS through echocardiographic evaluation is vital for risk stratification, guiding therapy, and improving outcomes in this high-risk population. Thus, evaluating echocardiographic parameters in ACS patients with concomitant COPD warrants focused attention and tailored approaches.

Study Design: Single-center, descriptive, observational, cross-sectional study.

Study Area: Nilratan Sircar Medical College and Hospital, Department of Cardiology, A.J.C. Bose Road, Kolkata – 700014.

Study Setting: In-patients admitted to the male ward, female ward, and Intensive Coronary Care Unit (ICCU) of the Department of Cardiology.

Study Timeline: The 18-month study period was divided into predefined stages.

Place of Study: Department of Cardiology, Nilratan Sircar Medical College and Hospital, 138 A.J.C. Bose Road, Kolkata – 700014.

Study Duration: 18 months, from 1st May 2023 to 31st October 2024.

Study Population: Adult patients with Acute Coronary Syndrome (ACS) who also have Chronic Obstructive Pulmonary Disease (COPD) and are admitted to the Department of Cardiology at NRS Medical College and Hospital.

Sample Size: 100 patients with Acute Coronary Syndrome, including individuals with and without COPD.

Sampling Design: Based on hospital records, approximately 10 patients are admitted weekly to the cardiology in-patient department. After matching for age, sex, and other baseline characteristics, consecutive eligible patients with ACS were included in the study. Patients with and without COPD were included at a 1:1 ratio.

Selection criteria:

Inclusion Criteria:

• Adult patients with COPD presenting as acute coronary syndrome with results of current or recent (not older than six months prior to AMI) pulmonary function test (PFTs)
• STEMI as defined by the European college of cardiology (ESC) and American association of cardiology (ACC)
• NSTEMI as defined by the European college of cardiology (ESC) and American association of cardiology (ACC)
• Unstable angina as defined by the European college of cardiology (ESC) andAmerican association of cardiology (ACC)
• Patients giving the consent for coronary

Exclusion Criteria:

• Patients who will not give consent
• Patients with rheumatic heart diseases
• Patients with congenital heart diseases
• Patients who will not undergo coronary angiogram
• Patients with chronic stable angina

Statistical Analysis: For statistical analysis, data were initially entered into a Microsoft Excel spreadsheet and then analyzed using SPSS (version 27.0; SPSS Inc., Chicago, IL, USA) and GraphPad Prism (version 5). Numerical variables were summarized using means and standard deviations, while categorical variables were described with counts and percentages. Two-sample t-tests, which compare the means of independent or unpaired samples, were used to assess differences between groups. Paired t-tests, which account for the correlation between paired observations, offer greater power than unpaired tests. Chi-square tests (χ² tests) were employed to evaluate hypotheses where the sampling distribution of the test statistic follows a chi-squared distribution under the null hypothesis; Pearson's chi-squared test is often referred to simply as the chi-squared test. For comparisons of unpaired proportions, either the chi-square test or Fisher’s exact test was used, depending on the context. To perform t-tests, the relevant formulae for test statistics, which either exactly follow or closely approximate a t-distribution under the null hypothesis, were applied, with specific degrees of freedom indicated for each test. P-values were determined from Student's t-distribution tables. A p-value ≤ 0.05 was considered statistically significant, leading to the rejection of the null hypothesis in favour of the alternative hypothesis.

Table 1: Association between Age in Group, Gender, Marital Status, ACS-STEMI, ACS- NSTEMI, Type of MI: Group

Table 2: Distribution of mean Age, Signs Pulse, Signs SBP, Signs DBP, BMI and Number of Vessel Outcomes: Group

Table 3: Association between ECHO ECHO RWMA, ECHO Wall Motion Score, ECHO Diastolic Dysfunction (Grade) and ECHO MR grade: Group

Table 4: Distribution of mean Age, Signs Pulse, Signs SBP, Signs DBP, BMI and Number of Vessel Outcomes: Group

Figure 1:  Association between ECHO RWMA: Group

Figure 2:  Distribution of ECHO IVS, ECHO PW, ECHO LVIDD, ECHO LVIDS, ECHO LA size and LVEF (%): Group

In this study comparing ACS patients with and without COPD, a significant difference was observed in the age group distribution (p = 0.0071). A higher proportion of COPD patients were aged ≤30 years (26% vs. 10%) and 41–50 years (24% vs. 10%), while the 31–40 age group was more prevalent in non-COPD patients (80% vs. 50%). No statistically significant differences were found in gender distribution (p = 0.3997), with both groups being predominantly male, or marital status (p = 0.1531), as most patients were married in both groups. Similarly, the distribution of ACS types (STEMI and NSTEMI) did not differ significantly between groups (p = 0.5049 for both), nor did the type of myocardial infarction (AWMI, IWMI, ALWMI, IWMI with RVMI), with p = 0.504. Overall, apart from age distribution, no other demographic or clinical characteristics showed significant differences between ACS patients with and without COPD. The mean age of ACS patients with COPD was significantly lower than that of those without COPD (34.92 ± 5.04 vs. 39.26 ± 3.53, p < 0.0001). Systolic blood pressure was also significantly lower in the COPD group (117.24 ± 15.89) compared to the non-COPD group (124.36 ± 16.34, p = 0.0295). There were no significant differences in pulse rate (83.3 ± 19.88 vs. 86.92 ± 15.35, p = 0.3107), diastolic blood pressure (76.6 ± 9.48 vs. 79.08 ± 8.41, p = 0.1696), or BMI (25.4 ± 2.11 vs. 25.22 ± 2.13, p = 0.6755) between the groups. However, the number of vessel involvements was significantly higher in patients with COPD (1.82 ± 0.84) than in those without COPD (1.50 ± 1.12, p = 0.0332). Echocardiographic findings showed no significant differences between ACS patients with and without COPD. The most common regional wall motion abnormality (RWMA) pattern was anterior, anteroseptal (34% vs. 40%), followed by inferior and inferoseptal (38% vs. 30%), with a p-value of 0.745. Wall motion scores were also similar across groups, with the majority having a score of 1.2 (70% vs. 68%, p = 0.565). Diastolic dysfunction was mainly Grade 1 in both groups (56% vs. 58%), though Grade 3 was observed only in the COPD group (8%), but the difference was not significant (p = 0.1195). Most patients had mild mitral regurgitation (Grade 1) in both groups (78% vs. 86%), with no significant difference (p = 0.4222). Echocardiographic parameters showed no significant differences between ACS patients with and without COPD. Interventricular septal thickness was 10.74 ± 1.59 mm in the COPD group and 10.86 ± 1.43 mm in the non-COPD group (p = 0.6921), while posterior wall thickness was 11.16 ± 1.78 mm vs. 11.7 ± 1.59 mm (p = 0.1129), respectively. LVIDD (50.42 ± 3.15 mm vs. 50.92 ± 3.48 mm, p = 0.4532) and LVIDS (34.9 ± 3.64 mm vs. 35.4 ± 3.68 mm, p = 0.4961) were also comparable. Left atrial size was 32.22 ± 2.79 mm in COPD patients and 32.4 ± 2.74 mm in non-COPD patients (p = 0.7454). PASP was similar (31.84 ± 6.01 mmHg vs. 32.48 ± 5.24 mmHg, p = 0.5719), as was left ventricular ejection fraction (47.02 ± 8.25% vs. 46.7 ± 6.77%, p = 0.8326).

In this study, age distribution emerged as the only significant demographic difference between ACS patients with and without COPD, with younger age groups (≤30 and 41–50 years) being more prevalent among COPD patients. This may suggest earlier onset or accelerated cardiovascular risk in COPD individuals. Other factors, including gender, marital status, ACS type, and infarction type, showed no significant variation, indicating comparable clinical presentations across groups aside from age.

Furthermore, Smith et al. [7] (2018) conducted a study evaluating the demographic characteristics and outcomes of ACS patients with COPD. Their results also indicated that while COPD patients were generally younger than their non-COPD counterparts, other demographic and clinical characteristics, such as gender, marital status, and infarction type, did not significantly differ between the two groups. They concluded that the association between COPD and early-onset cardiovascular disease could be attributed to shared risk factors, such as smoking and systemic inflammation, which influence the development of both conditions. Both studies, like ours, emphasize the need to consider COPD as an independent risk factor for early cardiovascular events and highlight the complexity of managing ACS in COPD patients, even when basic demographic and clinical characteristics are similar between groups.

In this study, ACS patients with COPD were significantly younger than those without COPD, highlighting an earlier onset of cardiovascular issues in this population. Systolic blood pressure was also lower in the COPD group, suggesting possible cardiovascular adaptations in COPD patients. No significant differences were observed in pulse rate, diastolic blood pressure, or BMI between the groups. Interestingly, patients with COPD had a significantly higher number of vessel involvements, indicating a more extensive coronary artery involvement in these patients.

In similar study by Andell et al.[8] (2015) found that among patients undergoing PCI for ACS, COPD patients had a 48% rate of multivessel disease compared to 35% in non-COPD patients, supporting the notion of more diffuse atherosclerosis in the COPD group [2]. This aligns with our findings where the mean number of vessels involved was significantly higher in the COPD group (1.82 vs. 1.50, p = 0.0332).

In our study, Echocardiographic findings revealed no significant differences between ACS patients with and without COPD. The most common regional wall motion abnormality (RWMA) pattern was anterior, anteroseptal, observed in 34% of the non-COPD group and 40% of the COPD group, followed by inferior and inferoseptal in 38% and 30%, respectively, with a p-value of 0.745.

In a study by Huang et al.[9] (2016), anterior and anteroseptal wall motion abnormalities were the most frequently observed patterns in ACS patients, occurring in 36% of non-COPD and 41% of COPD patients, closely mirroring your findings of 34% and 40%, respectively. Inferior wall involvement was also common, reported in 35% of non-COPD and 28% of COPD cases, which is similar to your observation (38% vs. 30%).

Wall motion scores were similar between groups, with the majority scoring 1.2. Diastolic dysfunction predominantly presented as Grade 1 in both groups, with Grade 3 observed only in the COPD group (8%), although this difference was not significant. Most patients in both groups had mild mitral regurgitation (Grade 1), with no significant difference observed. Overall, these results suggest that while there are minor variations, echocardiographic findings do not significantly differ between ACS patients with and without COPD.

In this study, Echocardiographic parameters showed no significant differences between ACS patients with and without COPD. Measurements of interventricular septal thickness, posterior wall thickness, left ventricular internal dimensions (LVIDD and LVIDS), and left atrial size were similar across both groups, indicating comparable structural cardiac characteristics. Pulmonary artery systolic pressure (PASP) and left ventricular ejection fraction (LVEF) also showed no significant differences. These findings suggest that, despite the presence of COPD, there is no notable impact on key echocardiographic parameters in ACS patients.

Similar findings were reported by Gülmez et al. [10] (2015), who evaluated 120 patients with ACS and found no significant differences in LVEF (46.1% in COPD vs. 47.4% in non-COPD, p = 0.589) or PASP (31.6 mmHg vs. 32.9 mmHg, p = 0.471) between the groups. They concluded that COPD does not significantly alter left ventricular function or pulmonary pressures in ACS patients.

We concluded that echocardiographic evaluation of ACS patients with and without COPD revealed no significant differences in key structural and functional parameters, including left ventricular dimensions, ejection fraction, and pulmonary artery pressures. While COPD patients presented at a younger age and showed greater coronary vessel involvement, their echocardiographic profiles remained largely comparable to non-COPD patients. Regional wall motion abnormalities and diastolic dysfunction patterns were similarly distributed across both groups. These findings suggest that despite more extensive coronary disease, COPD does not significantly alter echocardiographic presentations in ACS, reinforcing the utility of echocardiography for assessment and management in this population.

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