ISCHEMIC MITRAL REGURGITATION: PROBLEM EXTENT IN CARDIOVASCULAR SURGERY CLINIC

Abstract

The aim of the study was to evaluate the prevalence, etiology, mechanisms and severety of all cases of MR, including IMR, in the patients population with suspected or proved CAD before coronary arteries evaluation and surgery or intervention. Materials and methods: The study prospectively included 370 patients with verified or suspected (angina pectoris suspicion or manifested CHF) CAD of all clinical forms (stable, unstable, post-AMI, prior revascularization, etc.). MR evaluation by TTE included examining type of MR (organic or functional, Carpentier type) and its severity by vena contracta (VC) width and establishing effective regurgitant orifice (ERO) and regurgitant volume (RVol) by PISA method according to existing guidelines. Additional criteria (left atrium (LA) dimensions, LV diastolic filling and filling pressure markers, pulmonary veins flow and secondary pulmonary hypertension and right chambers involvement, etc.) were also widely used. Results: Majority of all patients were men – 280 out of 370 pts (75.7%). Mean age of pts was 62.4±8.96 years, and men were in general significantly younger (61.5±9.2 vs. 65.3±7.6 years, p=0.0004). 145 (39.2%) pts had verified AMI previously (126 men and 19 women, p<0.0001). 22 (5.95%) pts previously underwent CABG surgery (19 men and 3 women, p<0.0001), and 99 patients – PCI with coronary stenting (81 men and 18 women, p<0.0001). 42 (11.3%) pts proved to have no significant CAD as per CAG results: 24 (57.1%) pts had no significant cardiac pathology at all, 12 (28.6%) pts had uncomplicated essential hypertension, 5 (11.9%) pts had non-coronary dilated cardiomyopathy (DCM) and 1 (2.4%) pt had non-obstructive hypertrophic cardiomyopathy (HCP) with clean coronary arteries. In patients with CAD MR is a frequent finding (up to one-half of the studied population) regardless of gender. Predominant majority (84.1%) of MR according to TTE findings is mild (grade I), without significant influence upon heart load and remodeling, and, thus, requiring no additional surgeon interventions. Most of cases of such pathological MR resolved after myocardial revascularization or sustained without dynamics being physiological (13.2% of all MR cases). Most of moderate-to-severe MR cases were classified as IMR, being accompanied by appropriate LV remodeling features, requiring revascularization and/or mitral valvuloplasty or replacement (all cases of severe IMR or organic MR). Correlations results of MR ERO and RVol with certain heart chambers remodeling and load indices seem to make them a “gold standard” for MR severity evaluation, especially in CAD patients with potential indications for MV surgery that should accompany surgeon revascularization, as it is widely accepted today. Conclusions: In the patients with various forms of chronic and acute CAD IMR is a frequent finding, but the majority of MR cases are mild and requiring no additional interventions. No gender difference in MR prevalence were found. Severe MR cases in all CAD patients population are rather rare (below 10%), but always require surgical repair. Moderate-to-severe IMR is the most frequent (approximately 75%) etiology for significant MR in CAD patients, requiring close TTE follow-up for optimal intervention timing on the basis of left and right chambers remodeling and load indices. MR ERO and RVol are trustworthy quantitative MR severity indices, significantly correlating with main LV and LA remodeling and load indices, as well as with some secondary right chambers overload predictors.