Transcatheter paravalvular leak closure and hemolysis - a prospective registry

Paravalvular leak (PVL) related to a surgical prosthetic valve may be associated with clinically significant hemolysis. The influence of transcatheter PVL closure (TPVLC) on hemolysis remains uncertain.

The prospective registry included patients undergoing TPVLC due to PVL-related heart failure and/or hemolysis. Procedural data, laboratory markers of hemolysis and heart failure status were recorded at baseline, discharge and at 1- and 6-month follow-up.

Of 116 patients from all those qualified for TPVLC, 79 fulfilled the inclusion/exclusion criteria. Hemolysis was significantly more frequent in patients with mitral location of PVL and with calcifications in its channel. After TPVLC prompt reduction of lactate dehydrogenase activity (617.0 (342.0-899.0) vs. 397 (310.0-480.5) IU/l, p < 0.05) and gradual resolution of anemia (hemoglobin (HGB) 11.7 (10.4-13.8) vs. 13.4 (12.9-13.8) g%, p < 0.05) over 6 months were noted. Effective closure of PVL (> 90% reduction of PVL cross-sectional area) resulted in a more prominent increase of red blood cell count and HGB than in patients with residual regurgitation. The TPVLC-related exacerbation of hemolysis was recorded in 14 patients. Its risk was aggravated by presence of significant hemolysis at baseline or residual flow either by a partially uncovered channel or across the occluder. Reduction of hemolysis after successful TPVLC was sustained in 6-month follow-up.

Risk factors for PVL-related hemolysis were the presence of calcifications in the defect and mitral location of PVL. The TPVLC effectively reduced hemolysis if at least 90% reduction of PVL cross sectional area was achieved. The effect was sustained in 6-month follow-up. Incomplete closure of PVL may increase the magnitude of hemolysis after TPVLC, but it occurred rarely.