Prognostic value of low-dose dobutamine stress echocardiography in patients with aortic stenosis and impaired left ventricular function

Introduction

The aim of this multicenter, prospective study was to evaluate the long-term prognostic value of low-dose dobutamine stress echocardiography (LDDSE) in patients with aortic stenosis (AS) and depressed left ventricular (LV) function.

Material and methods

The study group comprised 39 patients (34 male, mean age 59 ±13 years) with AS (peak gradient > 25 mm Hg), LV ejection fraction (LVEF) ≤ 45% and low transaortic gradient (peak gradient ≤ 45 mm Hg, mean gradient ≤ 35 mm Hg). The qualification for subsequent therapeutic procedures was based on generally accepted indications. All patients underwent LDDSE and coronary angiography. Twelve months after LDDSE patients underwent control resting echocardiography and clinical evaluation.

Results

Twenty-seven (69.2%) patients had preserved contractile reserve. In this subgroup, true-severe AS was diagnosed in 12 patients, whereas pseudo-severe AS was found in 15 patients. Nine patients with true-severe AS, 2 patients with pseudo-severe AS and 7 patients without contractile reserve were referred for surgical treatment. The independent risk factors of death during follow-up were: aortic valve area (AVA) at peak stress < 0.8 cm² (OR 1.4; p = 0.003) and LVEF at rest < 35% (OR 6.8; p = 0.05). The independent risk factors of composite end-point (death or myocardial infarctions or pulmonary edema) were: AVA at stress < 0.8 cm² (OR 4.0; p = 0.03), absence of AVA increase during LDDSE (OR 5.7; p = 0.005), absence of contractile reserve (OR 4.5; p = 0.01) and presence of significant CAD (OR 6.9; p = 0.02).

Conclusions

In patients with AS and depressed LVEF, LDDSE is a useful tool for long-term risk stratification.