Hemodynamic effects of inhaled nitric oxide in women with mitral stenosis and pulmonary hypertension.

Mitral stenosis (MS) is associated with elevated left atrial pressure, increased pulmonary vascular resistance (PVR), and pulmonary hypertension (PH). The hemodynamic effects of inhaled nitric oxide (NO) in adults with MS are unknown. We sought to determine the acute hemodynamic effects of inhaled NO in adults with MS and PH. Eighteen consecutive women (mean age 58 +/- 15 years) with MS and PH underwent heart catheterization. Hemodynamic measurements were recorded at baseline, after NO inhalation at 80 ppm, and after percutaneous balloon valvuloplasty (n = 10). NO reduced pulmonary artery systolic pressure (62 +/- 14 mm Hg [baseline] vs 54 +/- 15 mm Hg [NO]; p <0.001) and PVR (3.7 +/- 2.5 Wood U [baseline] vs 2.2 +/- 1.4 Wood U [NO]; p <0.001). NO had no effect on mean aortic pressure, left ventricular end-diastolic pressure, left atrial pressure, cardiac output, or systemic vascular resistance. Mitral valve area increased after valvuloplasty (0.9 +/- 0.2 cm2 [baseline] vs 1.6 +/- 0.3 cm2 [postvalvuloplasty]; p <0.001). A decrease in left atrial pressure (25 +/- 4 mm Hg [baseline] vs 17 +/- 4 mm Hg [after valvuloplasty]; p <0.001) and pulmonary artery systolic pressure (58 +/- 12 mm Hg [baseline] vs 45 +/- 8 mm Hg [after valvuloplasty]; p <0.001) was observed after valvuloplasty. No change in cardiac output or PVR was observed. Thus inhaled NO, but not balloon valvuloplasty, acutely reduced PVR in women with MS and PH. This suggests that a reversible, endothelium-dependent regulatory abnormality of vascular tone is an important mechanism of elevated PVR in MS.

Hemodynamic effects and long-term outcome of percutaneous balloon valvuloplasty in patients with mitral stenosis and atrial fibrillation.

BACKGROUND: The presence of atrial fibrillation (AF) has been identified as a predictor of a suboptimal result in some patients undergoing percutaneous balloon valvuloplasty in the treatment of symptomatic rheumatic mitral stenosis. HYPOTHESIS: Atrial fibrillation adversely affects the short- and long-term outcome of patients with mitral stenosis undergoing percutaneous balloon valvuloplasty. METHODS: A retrospective chart review of 104 consecutive patients with rheumatic mitral stenosis undergoing percutaneous balloon valvuloplasty was performed. A successful procedure was defined as a final mitral valve area > or = 1.5 cm2 and the absence of a complication. Endpoints included freedom from mitral valve replacement, death, and repeat balloon valvuloplasty at 5 years. RESULTS: A successful procedure was obtained in 89% of patients with sinus rhythm and in 78% of patients with AF (p = NS). Patients in sinus rhythm had a greater cardiac output resulting in a larger final valve area than patients in AF (1.8 vs. 1.6 cm2, p < 0.05). Freedom from valve replacement, death, and repeat balloon valvuloplasty at 5 years was 75% for patients in AF and 76% for patients in sinus rhythm (p = NS). Lower postprocedure mitral regurgitation grade and absence of prior commissurotomy were the only independent predictors of event-free survival. CONCLUSIONS: Patients with mitral stenosis and AF have lower cardiac outputs and gradients than patients with sinus rhythm, despite similar valve areas. The long-term outcome of balloon valvuloplasty is independent of the initial cardiac rhythm.

Results of aortic valve replacement for aortic stenosis with relatively low transvalvular pressure gradients.

Fifty-two patients with low gradient critical aortic stenosis who underwent aortic valve replacement were found to have a perioperative mortality of 11% and an 8-year actuarial survival of only 29%. No hemodynamic variables, including valvular resistance, predicted long-term outcome, and the only clinical variable that predicted long-term survival was the absence of coronary artery disease.

Hemodynamic assessment of patients with low-flow, low-gradient valvular aortic stenosis.

In aortic stenosis (AS), conventional indexes of severity vary with changes in transvalvular flow. It is important to determine the true severity of obstruction because AS in the presence of low cardiac output and low gradient is associated with high mortality during aortic valve replacement. This study compares 3 indexes of stenosis severity at different transvalvular flow rates in patients with low-flow, low-gradient critical AS. Eight patients with critical AS (valve area < or = 0.7 cm2), low cardiac output (< 4.0 L/min), and low mean transvalvular gradient (< or = 40 mm Hg) underwent hemodynamic assessment at baseline, after transvalvular flow was augmented with dobutamine, and after the valve opening was increased with percutaneous balloon aortic valvuloplasty. Severity of obstruction was assessed using 3 different measures: Gorlin formula calculated valve area, valvular resistance, and percentage left ventricular stroke work loss. Dobutamine infusion increased cardiac output by 35% and mean transvalvular gradient by 27%. The mean Gorlin formula calculated aortic valve area increased from 0.5 to 0.6 cm2 (p = 0.002). Percentage left ventricular stroke work loss increased from 23% to 28% (p = 0.03). Valve resistance was unchanged by dobutamine (350 to 310 dynes X sec X cm(-5); p = NS). Balloon valvuloplasty increased cardiac output 13% and decreased the gradient 31%; this resulted in an increase in the calculated valve area from 0.6 to 0.9 cm2 (p = 0.001). Percentage left ventricular stroke work loss decreased from 28% to 20% (p = 0.002), and valve resistance decreased from 310 to 181 dynes X sec X cm(-5) (p = 0.001) after valvuloplasty. We conclude that in patients with low-flow, low-gradient critical AS, valve resistance is the most flow-independent measure of severity of stenosis. All measures improve with percutaneous balloon aortic valvuloplasty.