Experimental Design and Study Population:
This study was a retrospective cohort investigation with a longitudinal follow-up. We collected the study data by reviewing patients’ electronic medical records who had undergone TAVR at the structural Heart unit of Gates Vascular Institute in Buffalo, NY. This unit is one of the busiest structural cardiology centers in the US and performs over 600 TAVR procedures per year. The University of Buffalo Institutional Review Board reviewed and approved this study. We took extreme caution to minimize the risk of the privacy leak of the participants during data collection and not to impact the rights and welfare of these patients adversely.
We screened 677 patients who underwent TAVR from 2012 -to 2017. Based on inclusion criteria, we included 272 patients for further analysis. Patients were identified from the locally collected national database registry and had if they did not meet the exclusion criteria. Follow-up echocardiographic data (postoperative, six months, then annual follow-ups) pertinent to ELI calculation and hemodynamic properties of the prosthesis were collected. Patients were followed after the procedure until the primary endpoint was met. The relevant clinical information was collected along the way. ELI values were compared to these post-procedural events to identify a trend and a cutoff ELI value at which these events become more likely to occur. Inclusion criteria were all patients who had undergone a successful TAVR procedure at the Gates Vascular Institute from 2012 to 2017. Exclusion criteria applied to patients who passed away due to vehicular accidents, homicide, suicide, pre-procedural terminal illnesses, and patients who were lost to follow-up.