LAUSR

Rheumatic mitral stenosis (MS) remains the most common type of valvular heart disease worldwide yet there are few studies on optimal timing of intervention in asymptomatic patients. Postulated benefits of intervention before symptom onset include prevention of left atrial dilation, atrial fibrillation (AF) and pulmonary hypertension leading to fewer thromboembolic events, less heart failure, preserved exercise capacity and in improved quality of life. In this issue of Heart, Kang and colleagues report a randomised clinical trial of in 374 patients with severe MS (valve area 1.0–1.5 cm) comparing early percutaneous mitral commissurotomy (PMC) to conventional care. The primary composite endpoint of PMCrelated complications, cardiovascular mortality, cerebral infarction and systemic thromboembolic events occurred in seven patients in the early PMC group (8.3%) compared with nine patients in the conventional care group (10.8%) (HR 0.77; 95% CI 0.29 to 2.07; p=0.61) at a median followup of 6 years (figure 1). Karthikeyan points out that there is only a sparse evidence base for management of mitral stenosis. Although this study by Kang and colleagues is commendable, replication in larger studies in countries with endemic rheumatic heart disease is needed. In the meanwhile, ‘even minimally symptomatic patients with severe MS often deteriorate, due to AF and fast ventricular rates, triggered by drug noncompliance or intercurrent illness. In such situations, patients may not have timely access to acute care (and emergency PMC), which may be lifesaving. Therefore, a case can be made for performing early PMC in asymptomatic patients with significant MS ( mitral valve area ≤1.5 cm, or ≤1.3 cm if body surface area is <1.5 m), provided the procedure can be performed safely (procedurerelated death or mitral regurgitation requiring surgery <3%). Close medical followup should be reserved for patients in sinus rhythm, without evidence of left atrial hypertension, or a propensity for haemodynamic deterioration or systemic embolism.’ Also in this issue of Heart, Garcia Granja and colleagues present an observational study of 605 patients with leftsided infective endocarditis. The 405 patients who underwent surgery during the active phase of the disease were compared with the 200 who received only medical therapy. On multivariable analysis, early surgery was a independent predictor of survival (OR 0.260, 95% CI 0.162 to 0.416), particularly in those at highest risk (predicted mortality 80%–100%: OR 0.08, 95% CI 0.021 to 0.299) and those with uncontrolled infection (figure 2). In the accompanying editorial, Donal and colleagues discuss the limitations of this study and provide the context that in ‘the largest retrospective study provided Division of Cardiology, University of Washington, Seattle, Washington, USA