Left Ventricular Hypertrophic Change Indicating Poor Prognosis in Patients with Normal-Flow, Low-Gradient Severe Aortic Stenosis with Preserved Left Ventricular Ejection Fraction

概要

Background: Risk stratification of normal-flow, low-gradient (NFLG) severe aortic stenosis (SAS) with preserved left ventricular (LV) ejection fraction (EF) remains unclear.

Methods: Of 289 consecutive patients diagnosed with SAS by aortic valve area <1.0 cm2 evaluated by echocardiography with the continuity equation between January 2013 and December 2015, 66 with NFLG-SAS (stroke volume index >35 mL/m2, mean pressure gradient <40 mmHg, LVEF ≥50%) were enrolled in this study; patients with bicuspid aortic valve, acute coronary syndrome, hemodialysis, or a history of aortic valve replacement (AVR) were excluded. Adverse events were defined as cardiovascular death, hospitalization for heart failure, and deteriorating condition requiring AVR. Factors associated with adverse events were investigated using a Cox proportional hazards model.

Results: Over a median of 675 days of follow-up, 25 adverse events were recorded: 4 cardiovascular deaths, 12 hospitalizations for heart failure, and 9 patients requiring AVR. In addition, there were 14 events of progression to high-gradient SAS. Multivariable analysis showed significant associations between adverse events and the presence of symptoms (hazard ratio [HR] 10.276; 95% confidence interval [CI] 3.724–28.357; P<0.001), LV hypertrophy ((LV mass index >115 and >95 mg/m2 for males and females, respectively; HR 3.257; 95% CI 1.172–9.050; P=0.024), and tricuspid regurgitation (TR) velocity (HR 2.761;
95% CI 1.246–6.118; P=0.012).

Conclusions: The presence of symptoms, LV hypertrophy, and high TR velocity could be reliable prognostic indicators and may require watchful waiting for timely AVR in patients with NFLG-SAS.