Impact of mitral regurgitation on long-term survival in patients with ischemic cardiomyopathy: efficacy of combined mitral valve repair and revascularization

Mitral regurgitation quantified by CMR 4D-flow is associated with microvascular obstruction post reperfused ST-segment elevation myocardial infarction

Objectives

Mitral regurgitation (MR) and microvascular obstruction (MVO) are common complications of myocardial infarction (MI). This study aimed to investigate the association between MR in ST-elevation MI (STEMI) subjects with MVO post-reperfusion. STEMI subjects undergoing primary percutaneous intervention were enrolled. Cardiovascular magnetic resonance (CMR) imaging was performed within 48-hours of initial presentation. 4D flow images of CMR were analysed using a retrospective valve tracking technique to quantify MR volume, and late gadolinium enhancement images of CMR to assess MVO.

Results

Among 69 patients in the study cohort, 41 had MVO (59%). Patients with MVO had lower left ventricular (LV) ejection fraction (EF) (42 ± 10% vs. 52 ± 8%, P < 0.01), higher end-systolic volume (98 ± 49 ml vs. 73 ± 28 ml, P < 0.001) and larger scar volume (26 ± 19% vs. 11 ± 9%, P < 0.001). Extent of MVO was associated with the degree of MR quantified by 4D flow (R = 0.54, P = 0.0003). In uni-variate regression analysis, investigating the association of CMR variables to the degree of acute MR, only the extent of MVO was associated (coefficient = 0.27, P = 0.001). The area under the curve for the presence of MVO was 0.66 (P = 0.01) for MR > 2.5 ml. We conclude that in patients with reperfused STEMI, the degree of acute MR is associated with the degree of MVO.

Effectiveness of revascularization interventions compared with medical therapy in patients with ischemic cardiomyopathy: A systematic review protocol

BACKGROUND

Cardiomyopathies is a group of heart diseases that directly affects the heart muscle, and their causes is not just high blood pressure, congenital and pericardial diseases but ischemic cardiomyopathy disease are also caused by vascular disorders, and to confirm the diagnosis, angiography is required. There are several methods for treating and controlling ischemic cardiomyopathy in world health systems and especially in the Iran health system, which include medical treatment, percutaneous coronary intervention (PCI), and coronary artery bypass graft (CABG).

METHODS

This systematic review will includes observational and interventional studies in English and Persian languages and evaluates effectiveness of revascularization interventions and medical therapy in patients with ischemic cardiomyopathy. Animal studies will not be considered. In this systematic review, our sources of information will be electronic databases, trial registries, and different types of grey literature. An electronic search is performed through PubMed, Cochrane library, Scopus, Web of Science, EMBASE, Tufts Medical Center Cost-Effectiveness Analysis Registry, NHS Economic Evaluations Database. To integrate the results of studies with similar results, meta-analysis will be used, for which Comprehensive Meta-Analysis (CMA) software will be used. Results are provided using relative risk with a 95% confidence interval for information.

RESULTS

The results of this systematic review will be published in a peer-reviewed journal.

CONCLUSION

To our knowledge, this systematic review will be the first to evaluate existing research on the effectiveness of revascularization interventions compared with medical therapy in patients with ischemic cardiomyopathy. The review will benefit patients, healthcare providers, and policymakers.

Mitral valve annuloplasty and myocardial revascularization in the treatment of ischemic dilated cardiomyopathy

The aim of this study was to examine perioperative mortality and morbidity and midterm results in patients undergoing coronary bypass graft and mitral valve annuloplasty with advanced dilated cardiomyopathy. Sixty-one patients with ischemic dilated cardiomyopathy underwent coronary artery bypass grafting and mitral valve annuloplasty between January 1998 and December 2003. Patients eligible for revascularization that presented a mild or more severe mitral valve regurgitation at echocardiography (effective regurgitant orifice > 0.2 cm(2)) were considered for annuloplasty with a Cosgrove ring. New York Heart Association class (NYHA) III/IV was present in 40 patients (66%) and Canadian Cardiovascular Society class III-IV in 19 (31%). A previous acute myocardial infarction was reported in 48 patients (79%). The mean number of graft anastomoses was 2.5 +/- 0.7 and the left internal mammary artery was used in 49 patients (80%). In-hospital mortality was 4.9% (3 patients), due to unsuccessful weaning from cardiopulmonary bypass, multiple organ failure, and stroke, respectively. Left ventricle ejection fraction improved from 28.9% +/- 5.2% preoperatively to 35.4% +/- 8.1% at follow-up (P = 0.0001) and a significant reduction in NYHA III/IV was detected: from 40 patients preoperatively (66%) to 14 (31%) at follow-up (P = 0.031). Midterm cardiac-related mortality rate was 3.4%. In our experience combined coronary artery bypass grafting and ring annuloplasty for ischemic dilated cardiomyopathy can be performed with acceptable risks for in-hospital mortality and morbidity. Midterm results show a good survival rate and a durable functional improvement in this subset of patients.

Effect of mitral valve geometry on valve competence

The aim of the investigation was to vary certain geometrical features of the mitral valve in vitro, in order to understand their role in valve function. Geometrical changes to mitral valve components are known to affect valve function, but complete understanding of how geometrical changes influence valve function is far from complete. Test apparatus has been used to apply pressure to porcine mitral valves. Porcine mitral valve specimens were tested both in their intact state and with a specific aspect of their geometry altered. The geometric parameters of the mitral valve varied were (1) the length between the papillary muscles and the mitral annulus (termed the annulo-papillary length), (2) the diameter of the left ventricle at the level of the papillary muscles, and (3) the mitral annular area. Six specimens were tested for each parameter investigated. A minimum annulo-papillary length was necessary to allow chordae tendineae to pull on the valve leaflets in order to prevent mitral valve failure; increasing this length further improved valve closure. Over the experimental range tested, left ventricular dilation at the level of the papillary muscles did not induce failure (P not significant). Increasing the mitral annular area was found to induce failure (P = 0.030 and P = 0.018 for medium and large annular diameters, respectively). The results demonstrate the importance of the geometry of mitral valve components on its function, and give insights into further experiments required to provide further understanding of the role of mitral valve geometry in its function. The results demonstrate that this in vitro method can be used to vary selected features of the geometry of the mitral valve.

Moderate-to-severe ischemic mitral regurgitation and multivessel coronary artery disease: Impact of different treatment on survival and rehospitalization

BACKGROUND

The outcome of moderate-to-severe ischemic mitral regurgitation with multivessel coronary artery disease is still debated. We analysed the effect of different treatments, i.e. medical therapy (MT), coronary artery by-pass grafting (CABG) alone and CABG with mitral valve surgery (MVS), on the survival and rehospitalization of these patients.

METHODS

Between 1990 and 2002, we identified 111 consecutive patients, aged 73+/-8 years, with chronic moderate-to-severe mitral regurgitation and multivessel coronary artery disease at cardiac catheterization, in absence of primary valve disease. Twenty-two patients were treated by MT, 50 by CABG and 39 by CABG+MVS. Overall, the median clinical and echocardiographic follow-ups were 34.9 and 14.6 months, respectively.

RESULTS

Groups differed significantly (p < 0.03) for left ventricular end-diastolic volume index (MT 153+/-54, CABG 125+/-35, CABG + MVS 129+/-38, ml/m2), ejection fraction (MT 35+/-14, CABG 38+/-13, CABG + MVS 50+/-14, %) and mammary artery graft use (CABG 60, CABG + MVS 74, %). While in-hospital mortality was higher in surgical patients (MT 13.6, CABG 18, CABG + MVS 17.9, %, p=0.09), 7-years mortality showed a trend in favour of CABG + MVS compared to other groups (MT 100, CABG 57, CABG + MVS 29, %, p = 0.1). After adjusting for baseline differences, CABG alone or with MVS had a 57% (HR 0.43, p = 0.005) and 53% (HR 0.47, p = 0.02) risk reduction of combined cardiac death and rehospitalization rate compared to MT. However, only CABG + MVS independently predicted mortality (risk reduction 65%, HR 0.35, p = 0.027).

CONCLUSIONS

In moderate-to-severe ischemic mitral regurgitation and multivessel coronary artery disease, surgery reduced total cardiac events but only a concomitant MVS significantly improved survival.