Predictors of mortality in patients undergoing percutaneous aortic valve implantation

Transcatheter aortic valve implantation (TAVI) became an attractive alternative to surgery for patients with severe aortic stenosis and high operative risk. The first multicenter randomized trial, conducted in such high risk cohort, showed 20% reduction in mortality in the group treated with TAVI compared to those treated with medical therapy (30.7% vs. 50.7% P=0.001) and a non-inferiority of TAVI compared to traditional valve surgical replacement for all-cause mortality at 1 year with, similar improvement of symptoms and physical performance. However, mortality rate of TAVI remains high (20-30% at one year). The purpose of this prospective single center study was to identify predictors of mortality and adverse events in patients undergoing TAVI in order to be able to select the ones who benefit most from the procedure.

Between June 2009 and June of 2011, 118 patients with severe aortic stenosis treated with TAVI at IRCCS Humanitas Clinical Institute were included in a prospective registry. Pre procedural clinical and ecocardiographic evaluations, surgical risk estimation, and procedural complications, defined by VASC criteria, were recorded. Clinical and echocardiographic evaluations were performed at 1, 6 and 12 months after the implants. To investigate the predictors of mortality, clinical and anatomical characteristics of alive patients were compared with those of death ones at one month and one year follow-up.

The procedural success occurred in 92.4% of procedures; vascular complications (33%), bleeding complications (22%), postimplant paravalvolar grade ≥2 AR (20.4%) a new permanent pacemaker implant (19.7%), were the most common complications. Survival for the whole cohort at 30 days was 6.8%, survival at one year was 82.2%. In the logistic regression test, one month mortality was significantly adversely affected by the renal functional status (odd ratio 0.9356), by a previous history of coronary artery bypass grafting (odd ratio 39) and by the mean aortic annular diameter (odd ratio 0.512) (P=0.0005). One year mortality was influenced by high EuroSCORE (odd ratio 1.0399) and the presence of hemodynamically significant prosthetic regurgitation (odd ratio 3.8438).

TAVI procedure, in high risk patients with critical aortic stenosis, can be accomplished with low procedural mortality. The worst outcome affects particularly patients with renal insufficiency and previous coronary bypass. However, the long-term mortality remains high due to the poor baseline conditions, mainly related to co-morbidity and to the presence of residual post-procedural aortic insufficiency.