Acute and chronic efficacy of percutaneous transvenous mitral commissurotomy: implications for patient selection.

Despite the introduction of penicillin and improvements in the standard of living and delivery of primary health care, rheumatic mitral stenosis remains an important medical problem in the United States as well as abroad. In the past decade, percutaneous transvenous mitral commissurotomy (PTMC) with the Inoue balloon catheter has emerged as a safe and efficient treatment for symptomatic patients and has supplanted surgical commissurotomy as the initial treatment approach in the majority of patients with mitral stenosis. Acutely, balloon valvuloplasty can achieve an approximately 100% increase in mitral valve area and markedly improve symptoms, including dyspnea and NYHA functional class. However, peak oxygen consumption during exercise may not increase acutely, and the subjective improvement in dyspnea is likely related to a diminished work of breathing. Chronically, the hemodynamic improvements achieved with PTMC are maintained (up to 5 yr) with a low rate of recurrent symptoms due to restenosis, production, or progression of mitral regurgitation or inadequate initial dilation. Freedom from death, mitral valve replacement, and repeat valvuloplasty range between 51% and 84% at 4-5 yr postprocedure, depending on various selection criteria. Functional improvement, as measured by exercise capacity with respiratory gas analysis, occurs over several months suggesting that chronic peripheral alterations in the skeletal muscle and vasculature of patients with long-standing mitral stenosis may limit the initial benefit of successful PTMC until vascular remodeling or aerobic training can allow the skeletal musculature to use the greater cardiac output afforded by successful PTMC. Careful patient selection is essential to obtain the best hemodynamic improvement with the lowest rate of complications.(ABSTRACT TRUNCATED AT 250 WORDS)