• Interventional Techniques & Devices Clinical Trials
• Heart Failure
• Valvular Disease

Mitral valve (MV) repair during coronary artery bypass grafting (CABG) may be associated with improved survival compared with CABG alone in patients with low left ventricular ejection fraction (LVEF) and moderate to severe mitral regurgitation (MR), according to new findings from the Surgical Treatment for Ischemic Heart Failure trial [STICH; NCT00023595].

Marek A. Deja, MD, Medical University of Silesia, Katowice, Poland, reported results from a subanalysis of the STICH trial in patients with MR.

In the STICH study, 1212 patients with LVEF <35% who were suitable candidates for CABG were randomly assigned to CABG (n=610) or medical therapy alone (n=602). In the primary analysis, there was no difference in all-cause mortality between CABG and medical therapy alone (36% vs 41%; HR, 0.86; 95% CI, 0.72 to 1.04; p=0.12). While the primary result was neutral, CABG was associated with reductions in some secondary endpoints, including the risk of cardiovascular (CV) death (28% vs 33%; HR, 0.81; 95% CI, 0.66 to 1.00; p=0.05) and the composite endpoint of all-cause mortality or CV hospitalization (58% vs 68%; HR, 0.74; 95% CI, 0.64 to 0.85; p<0.001) [Velazquez EJ et al. N Engl J Med 2011].

At baseline, MR was present in 64% of patients and classified as mild, moderate, and severe in 46%, 15%, and 3% of the patients who were randomized in STICH, respectively, underscoring the high prevalence of MR in candidates for CABG. The decision of whether or not to treat MR was left to the surgeon. In the current analysis, investigators examined the relationship of MR severity and survival and compared outcomes in patients with moderate-severe MR who received mitral repair versus those who did not.

In patients who were randomized to medical treatment, mortality was higher in patients with increasingly more severe MR (30% with no/trace MR, 47% with mild MR, 55% with moderate-severe MR). Compared with patients with no or trace MR, patients with moderate or severe MR had nearly double the risk of death from all causes (HR, 1.97; 95% CI, 1.37 to 2.83), while those with mild MR had a 60% increase in all-cause mortality (HR, 1.60; 95% CI, 1.18 to 2.18).

After 6 years of follow-up, CABG was not associated with decreased mortality relative to medical therapy alone in patients with no or trace MR (28% vs 30%; HR, 0.87; 95% CI, 0.61 to 1.24); however, CABG was associated with a reduced risk of death in patients with mild MR (31% vs 47%; HR, 0.64; 95% CI, 0.48 to 0.85).

In the small subgroup of patients with moderate or severe MR (n=195), there was no survival advantage with CABG compared with medical therapy alone (HR, 0.86; 95% CI, 0.57 to 1.29) or with CABG and mitral repair (HR vs medical therapy 1.13, 95% CI, 0.69 to 1.86). However, after adjustment for baseline prognostic variables, the combination of CABG and MV repair was associated with a lower hazard of mortality compared with CABG alone (HR, 0.45; 95% CI, 0.23 to 0.90) and was associated with a trend toward lower mortality compared with medical therapy alone (HR, 0.66; 95% CI, 0.40 to 1.11).

The authors conclude that in patients with severe left ventricular dysfunction and mild MR, CABG alone improves survival, while in patients with moderate–severe MR, adding mitral repair to CABG tends to decrease perioperative risk and increase survival compared with CABG alone or medical therapy alone.

• © 2011 MD Conference Express