177 Does transcutaneous aortic valve implantation induce myocardial injury?

Increased cardiac troponin is observed after valvular surgery, indicating perioperative myocardial injury, although the clinical significance of this elevation remains controversial. The current study was designed to evaluate the frequency of troponin elevation and the degree of myocardial injury after transcutaneous aortic valve replacement (TAVR), a new procedure for the treatment of high surgical risk patients (pts) with degenerative aortic stenosis (AS).Methods51 consecutive pts (84±6 years old) with severe symptomatic AS and a high surgical risk for valve replacement had retrograde TAVR using the Edwards-Sapien balloon expandable heart valve. 27% of pts had previous coronary artery bypass graft and 25% had previous coronary angioplasty. At the time of valve implantation, 35% of pts had at least one significant coronary stenosis (> 50%). TAVR was performed under local anesthesia after surgical cut-down of the femoral artery. A 23 or 26 mm transcutaneous valve was implanted during a brief period of rapid pacing (200 to 220 bpm). Cardiac Troponin I was measured using the DPC Immulite 2500 assay (lower limit of detection: 0.2μg/l, suggested diagnostic value for myocardial infarction: 1.0μg/l) before, 8 hours and 24 hours after TAVR.ResultsAfter TAVR, the effective orifice area increased from 0.64±0.14 to 1.80±0.3 cm2 (p< 0.0001) and the transvalvular mean gradient decreased from 47±15 to 8±4 mmHg (p<0.0001). Troponin level was 0.07±0.15μg/l at baseline and significantly increased 8 hours (2.57±2.47μg/l) and 24 hours (4.82±8.02μg/l) after TAVR (p