Frequency and Echocardiographic Correlates of Right Ventricular Dysfunction in Patients With Old Myocardial Infarction and Reduced Ejection Fraction
TL;DR
RV dysfunction is highly prevalent in patients with old MI and reduced LVEF and was most frequent for strain-based indices, particularly RVGLS; however, no comparative discrimination or reclassification analysis was performed, so relative diagnostic performance against conventional indices cannot be inferred from these data.
Abstract
Background: Old myocardial infarction (MI) with reduced left ventricular ejection fraction (LVEF) is a major cause of cardiovascular morbidity and mortality, particularly in low- and middle-income countries. While left ventricular dysfunction has been extensively studied, right ventricular (RV) involvement remains underappreciated despite evidence of its prognostic relevance in other cohorts. This study aimed to determine the frequency of RV dysfunction and its echocardiographic correlates in patients with old MI and reduced LVEF. Methods: This was a single-centre, hospital-based, observational cross-sectional study conducted over 12 months (April 2021-March 2022) in the Department of Cardiology, Bangladesh Medical University (formerly Bangabandhu Sheikh Mujib Medical University), Dhaka, Bangladesh, following ethical approval. Adults aged >30 years with old MI documented by objective criteria, occurring more than three months before enrolment, and LVEF <40% were recruited by consecutive sampling from inpatient and outpatient services. The primary outcome was the frequency of RV dysfunction, defined a priori for each index as tricuspid annular plane systolic excursion (TAPSE) <17 mm, tricuspid annular systolic velocity (S′) <10 cm/s, RV fractional area change (FAC) <35%, myocardial performance index (MPI) ≥0.55, isovolumic relaxation time (IVRT) >30 ms, isovolumic acceleration (IVA) <1.1 m/s², RV global longitudinal strain (RVGLS) less negative than −17%, and RV free wall strain (RVFWS) less negative than −20%. The secondary outcome was the association between elevated pulmonary artery systolic pressure (PASP >35 mmHg) and each abnormal RV index. Binary logistic regression was performed with each RV index modelled separately as the dependent variable. Results: Of 195 patients screened, 85 were analysed (mean age 59.9 ± 8.1 years; 81.2% male; mean LVEF 32.1 ± 4.1%). Reduced TAPSE and S′ were each present in 62.4%, reduced FAC in 56.5%, elevated MPI in 55.3%, prolonged IVRT in 57.6%, and reduced IVA in 31.8%. Impaired RVGLS and RVFWS were observed in 76.5% and 71.8%, respectively. PASP >35 mmHg was detected in 38.8% and was associated with abnormal S′ (OR 6.39; 95% CI 1.11-36.73; p = 0.038) and prolonged IVRT (OR 8.79; 95% CI 1.72-44.93; p = 0.009). Regional RV wall motion abnormality was not associated with any RV functional index. Conclusion: RV dysfunction is highly prevalent in patients with old MI and reduced LVEF. Abnormality was most frequent for strain-based indices, particularly RVGLS; however, no comparative discrimination or reclassification analysis was performed, so relative diagnostic performance against conventional indices cannot be inferred from these data. Comprehensive RV assessment should be considered in this high-risk population.