MODERATE AORTIC STENOSIS IN HEART FAILURE PATIENTS - A POTENTIAL OPPORTUNITY FOR TRANSCATHETER AORTIC VALVE REPLACEMENT

Moderate aortic stenosis (AS) is not an indication for surgical valve replacement unless undergoing coronary artery bypass grafting (CABG). Since patients with a low ejection fraction (EF) are very sensitive to changes in afterload, moderate AS could have a negative impact on LV function and survival. Transcatheter aortic valve replacement (TAVR) represents a minimally invasive method to treat patients with aortic stenosis. Randomized studies comparing TAVR to medical therapy are currently enrolling heart failure patients with moderate stenosis. There is a paucity of data, however, about the prevalence of moderate aortic stenosis with heart failure. This is a retrospective cohort study of 2,217 patients enrolled in the Heart Failure clinic at the MUHC from 2007 to 2017, totaling 10,300 echocardiograms. Patients older than 18 years with a clinical diagnosis of heart failure with echocardiographic follow up were included. Post transplant patients and those on ventricular mechanical support or with previous AV replacement were excluded from the study. Echocardiographic data were parsed from the 10,300 TTE reports using software we developed, in Java language. The severity of aortic valve stenosis was classified according to the American Society of Echocardiography guidelines. There were 2217 patients included in the analysis. Final echo was used to get a snap-shot of number of patients with AS. The ejection fraction was reduced (<40%) in 73% of patients, whereas the remaining 27% had a preserved EF (>40%). Using the criteria for AS severity by AVA (i.e 1cm2 < AVA < 1.5cm2); 291 patients (13.1%) had moderate AS at any point during their follow-up, of which 40 patients progress to severe AS (13.7%). Using the mean gradient criteria (i.e. 20mmHg < MG < 40mmHg), we obtained 124 patients (5.6%); in the setting of the high prevalence of reduced EF in our population. When comparing patients with moderate AS to patients with no AS, the moderate group demonstrated worse LV remodelling with higher LV mass, lower stroke volume and a fall in EF. The moderate group also had higher pulmonary artery systolic pressures. Moderate AS is found in 13% of our heart failure population. Our results show that moderate AS is sufficient to have deleterious echocardiographic impacts in patients with pre-existing heart failure. This raises the question whether a fraction of there patients would benefit from aortic valve intervention (such as TAVR) before they progress to severe.