Systemic Hypertension in Low Gradient Severe Aortic Stenosis with Preserved Ejection Fraction
Background—Low gradient (LG) severe aortic stenosis (AS) with preserved ejection fraction (EF) is an increasingly recognized entity, and symptomatic patients may benefit from aortic valve replacement. However, systemic hypertension frequently coexists with LG severe AS, which itself may cause elevated left ventricular (LV) filling pressures with resultant symptoms of dyspnea.
Methods and Results—Symptomatic patients with hypertension (aortic systolic pressure>140 mmHg) and LG (mean gradient<40 mmHg) severe AS (aortic valve area<1 cm2) with preserved EF (EF>50%) who underwent invasive hemodynamic left and right heart catheterization received infusion of intravenous sodium nitroprusside to reduce blood pressure and arterial afterload. At baseline, patients had severe hypertension (aortic systolic pressure 176±26 mmHg), pulmonary hypertension (mean pressure 39±12 mmHg), elevated LV end diastolic pressure (19±5 mmHg) and reduced stroke volume (33±8 ml/m2). All measures of afterload were reduced with nitroprusside (p<0.001 for all). Nitroprusside reduced mean pulmonary artery pressure (25±10 mmHg) and LV end diastolic pressure (11±5 mmHg) (p<0.001 for both as compared to baseline). Aortic valve area (0.86±0.11 to 1.02±0.16 cm2, p=0.001) and mean gradient (27±5 to 29±6 mmHg, p=0.02) increased with nitroprusside.
Conclusions—Systemic hypertension in LG severe AS with preserved EF is associated with elevated LV filling pressures and pulmonary hypertension. Treatment of hypertension with vasodilator therapy results in a lowering of the total LV afterload, with a decrease in LV filling pressures and pulmonary artery pressures. These findings have important implications for the management of patients with LG severe AS with preserved EF and hypertension.
- Received April 5, 2013.
- Revision received July 11, 2013.
- Accepted July 24, 2013.