Ischemic mitral regurgitation (IMR) is associated with poor outcomes in patients with coronary artery disease. The impact of percutaneous coronary intervention (PCI) on patients with IMR is not well elucidated. We sought to determine the outcomes of patients with severe IMR who underwent PCI. Patients with severe (≥3+) IMR who underwent PCI from 1998 to 2010 were identified. Improvement in IMR was defined as reduction in severity from ≥3+ to ≤2+ without any other invasive intervention beyond PCI. Outcomes were compared between patients with and without improvement in IMR after PCI. One hundred thirty-seven patients with severe IMR were included in our study. After PCI, 50 patients (36.5%) had improvement in IMR with PCI alone and 24 patients (18.5%) required another intervention. Left atrial size was a significant predictor of improvement in IMR (odds ratio 0.39, 95% confidence interval 0.2 to 0.8). Left ventricular size decreased (systolic diameter 3.9 ± 0.3 vs 4.6 ± 0.2 cm, p = 0.0008 and diastolic diameter 5.2 ± 0.2 vs 5.7 ± 0.2 cm, p = 0.002) and ejection fraction increased (39.1 ± 4.0% vs 33.1 ± 1.9%, p = 0.002) significantly after PCI in the patients with improvement in IMR compared with patients without improvement. Patients with improvement in IMR had numerically better survival; however, it was not statistically significant (p log-rank = 0.2). In conclusion, 1/3 of the patients with IMR had improvement in severity of IMR with PCI alone. Improvement in IMR was associated with left ventricular reverse remodeling. Left atrial size was an important predictor of improvement in IMR after PCI.
Highlights
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We examined ischemic mitral regurgitation (IMR) after percutaneous coronary intervention (PCI).
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Mitral regurgitation (MR) improved in 1/3 of patients with only PCI.
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IMR improvement was sustained in 75% of patients.
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MR improvement was associated with reverse left ventricular remodeling.
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Left atrial size is the most important predictor of IMR improvement.
Coronary artery disease (CAD) may lead to left ventricular (LV) dilation and tethering of the papillary muscles, leading to malcoaptation of the mitral valve (MV) leaflets and causing ischemic mitral regurgitation (IMR), which results in greater mortality and morbidity. It remains unclear whether the IMR is causally related to increased mortality or is just a marker of worse ventricular dysfunction. Traditionally, patients with multivessel CAD (3-vessel CAD and/or left main disease) and moderate-to-severe IMR undergo MV repair (MVRe) and coronary artery bypass grafting (CABG). However, the MVRe does not impact long-term survival, and durability of the annuloplasty is questionable with some investigators demonstrating up to 66% recurrence in moderate-to-severe mitral regurgitation (MR). Recently, percutaneous strategies for MVRe have shown promising results for the treatment of IMR. MitraClip therapy can be effective in reducing mortality and morbidity in patients with IMR. In contrast, the impact of percutaneous coronary intervention (PCI) alone in patients with IMR remains controversial and poorly defined. Because many patients with CAD and IMR are referred for percutaneous MVRe, it is relevant to identify when PCI should first be performed and what are the expected outcomes. We therefore sought to determine the outcomes of patients with severe IMR undergoing PCI, with a focus to identify predictors for improvement in IMR severity.
Material and Methods
All adults (>18 years) with severe (≥3+) IMR who underwent PCI at our institution from January 1, 1998, to January 1, 2010, were identified by querying our interventional cardiology databases. IMR was defined as functional MR in the presence of significant CAD. By definition, such patients had no evidence of structural or primary MV disease defined as rheumatic MV disease, myxomatous degeneration, endocarditis, MV prolapse, ruptured chordae, ruptured papillary muscles, or other structural MV problems. Patients without follow-up echocardiogram after PCI or those who had undergone another invasive procedure including MVRe, heart transplantation, or cardiac resynchronization therapy-defibrillator (CRT-D) before PCI were excluded ( Figure 1 ). Baseline clinical characteristics, cardiac history, risk factors, family history, medications, and any available myocardial viability data before PCI were collected.
