Impact of Isolated Coronary Artery Bypass Grafting on Non-Organic Tricuspid Regurgitation Severity

Background: Moderate non-organic tricuspid regurgitation (TR) concomitant with coronary artery disease is not uncommon. Whether or not TR improves after pure coronary artery bypass grafting (CABG), however, is unclear. The aim of this study was to evaluate the effect of isolated CABG on moderate non-organic TR. Methods: This study recruited 50 patients (40% female, mean age: 65.38±8.01 years, mean left ventricular ejection fraction (LVEF): 45.74±13.05%) with moderate non-organic TR who underwent isolated CABG. TR severity before and after CABG was compared. Pulmonary arterial systolic pressure (PAPs) > 30mmHg and LVEF < 50% were considered elevated PAPs (EPAPs) and LV systolic dysfunction, respectively. Presence of Q-wave in leads II, III, and aVF was considered inferior myocardial infarction (inf. MI). Results: Pre-operatively, 81.5% of the patients had EPAPs, 16% right ventricle (RV) dilation, and 50% left ventricle (LV) and 16% RV systolic dysfunction. TR severity improved in 64% after CABG, whereas it remained unchanged or even worsened in others (P value < 0.001). Patients with inf. MI showed no improvement in TR, while patients without inf. MI had significant TR regression after CABG (P value=0.050). Improvement of TR severity after CABG was not related to pre-operative RV size and function, LV systolic function, or PAPs reduction. Conclusion: Although TR severity decreased remarkably after isolated CABG, a considerable number of the patients had no TR regression. In addition, only absence of inf. MI was significantly correlated to TR improvement after CABG. Further prospective studies with long-term follow-up are needed to determine the other factors predicting TR regression after isolated CABG.