Acceptability and psychometric properties of the Minnesota Living With Heart Failure Questionnaire among patients undergoing heart valve surgery: validation and comparison with SF-36.

BACKGROUND: Health-related quality of life (HQOL) enhancement is a major objective of valvular surgery (VS), but assessments have been limited primarily to generic measures that may not be optimally responsive to intervention. Disease-specific instruments have been used in heart failure (HF), commonly associated with valve disease, but have been neither validated nor routinely applied among patients undergoing VS. METHODS AND RESULTS: We administered the Minnesota Living with Heart Failure (MLHFQ) and SF-36 questionnaires preoperatively (T(0)) to 50 patients undergoing VS and at 1 (T(1)) and 6 months (T(2)) after VS. Performance of MLHFQ was evaluated and compared with SF-36. MLHFQ completion rates were >98% (NS vs. SF-36); Cronbach's alpha was > or = 0.9 (total score, dimensions), supporting internal reliability. Confirmatory factor analysis verified good model fit for physical/emotional domain items (relative chi-squares < 3.0, critical ratios > 2.0, both instruments), supporting structural validity. Spearman coefficients correlating MLHFQ with parallel SF-36 domains were moderate to high (0.6-0.9; P < or = .001: T(0)-T(2)), supporting convergent validity. Baseline HQOL was poorest in patients with HF (P < or = .05 [both instruments]), supporting criterion validity. Responsiveness (proportional HQOL change scores: T(0) vs. T(2)) to VS was greater with MLHFQ vs. SF-36 (P < or = .002). CONCLUSIONS: Among patients undergoing VS, the MLHFQ is highly acceptable and maintains good psychometric properties, comparing favorably with SF-36. These findings suggest its utility for measuring disease-specific HQOL changes after VS.

Prognostic value of exercise tolerance testing in asymptomatic chronic nonischemic mitral regurgitation.

In many heart diseases, exercise tolerance testing (ETT) has useful functional correlates and/or prognostic value. However, its predictive value in mitral regurgitation (MR) is undefined. To determine whether ETT descriptors predict death or indications for mitral valve surgery in patients with MR, we prospectively followed, for 7 +/- 3 end-point-free years, a cohort of 38 patients with chronic severe nonischemic MR who underwent modified Bruce ETT; all lacked surgical indications at study entry. Their baseline exercise descriptors were also compared with those from 46 patients with severe MR who, at entry, already had reached surgical indications. End points during follow-up in the cohort included sudden death (n = 1), heart failure symptoms (n = 2), atrial fibrillation (n = 4), left ventricular (LV) ejection fraction <60% (n = 2), LV systolic dimensions > or =45 mm (n = 12) and >40 mm (n = 11), LV ejection fraction <60% plus LV systolic dimensions > or =45 mm (n = 3), and heart failure plus LV systolic dimensions > or =45 mm plus LV ejection fraction <60% (n = 1). In univariate analysis, exercise duration (p = 0.004), chronotropic response (p = 0.007), percent predicted peak heart rate (p = 0.01), and heart rate recovery (p <0.02) predicted events; in multivariate analysis, only exercise duration was predictive (p <0.02). Average annual event risk was fivefold lower (4.62%) with an exercise duration > or =15 versus <15 minutes (average annual risk 23.48%, p = 0.004). Relative risks in patients with and without exercise-inducible ST-segment depression were comparable (< or =1.3, p = NS) whether defined at entry and/or during follow-up. Exercise duration, but not prevalence of exercise-inducible ST-segment depression, was lower (p <0.001) in patients with surgical indications at entry versus initially end-point-free patients. In conclusion, in asymptomatic patients with chronic severe nonischemic MR and no objective criteria for operation, progression to surgical indications generally is rapid. However, those with excellent exercise tolerance have a relatively benign course. Exercise-inducible ST-segment depression has no prognostic value in this population.