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.

Prognostic impact of systolic hypertension on asymptomatic patients with chronic severe aortic regurgitation and initially normal left ventricular performance at rest.

The influence of systolic hypertension (SH) on the natural history of chronic aortic regurgitation (AR) and the clinical effect of antihypertensive medication on patients who have hypertension and AR are incompletely defined. Therefore, we reviewed the clinical course of 80 unoperated patients who were entered prospectively into an assessment of natural history of AR and its predictors and were asymptomatic with normal left ventricular ejection fraction (LVEF) at rest at study entry; 30 of 80 patients had SH (systolic blood pressure >140 mm Hg); 20 of 80 patients (16 had SH) used antihypertensive drugs for the long term (not mandated by protocol). During an average 7.2-year event-free follow-up, 24 patients developed symptoms alone (n = 14), subnormal LVEF with or without symptoms (n = 8), or died suddenly (n = 2). SH tripled the average annual risk of cardiac events (8.47% vs 2.85%, p = 0.004). The effect of systolic blood pressure was independent of age, gender, diastolic blood pressure, LV diastolic dimension, fractional shortening, and LVEF at rest (p = 0.004 to <0.008). However, positive prognostic interactions existed between systolic blood pressure and pulse pressure (p <0.001), LVEF during exercise (p <0.001), change in LVEF from rest to exercise (p <0.001), and the contractility index (p <0.02). Among patients who had SH, antihypertensive therapy predicted increased event risk (average annual risk 15.46% vs 3.98%, p <0.02) and remained predictive when analysis was adjusted for potentially confounding subgroup variations at study entry (p <0.03, all models). In conclusion, SH portends poor clinical outcome in chronic severe AR. As a group, antihypertensive drugs do not mitigate outcome, although the effect of individual drugs is uncertain and at least some may be deleterious. The theoretically based practice of giving antihypertensive drugs to patients who have AR requires reexamination.