High body mass index is a risk factor for difficult deep sedation in percutaneous mitral valve repair

The safety and efficacy of deep sedation (DS) in MitraClip® procedures have been shown previously. However, clinical experience demonstrates that in some patients DS is difficult to achieve. We hypothesize that some patient characteristics can predict difficult DS.

We prospectively analysed 69 patients undergoing MitraClip® procedures using DS. Application of DS was graded as simple (group 1) or difficult (group 2) depending on a cumulative score based on one point for each of the following criteria: decrease in oxygen saturation, retention of carbon dioxide, disruptive body movements, and the need for catecholamines. Patients with one point or less were classified as group 1, and patients with two or more points were classified as group 2.

In 58 of 69 patients (84.1%), the performance of DS was simple, while in 11 patients (15.9%), DS was difficult to achieve. Patients with difficult DS were characterized by a higher body mass index (33.7 ± 6.0 kg/m2 vs. 26.1 ± 4.1; p = 0.001), younger age (67 ± 13 years vs. 75 ± 13 years; p = 0.044), and reduced left ventricular ejection fraction (36% ± 10 vs. 45% ± 14; p = 0.051) and presented more often with an obstructive sleep apnoea syndrome (6.9% vs. 45.5%; p = 0.003). In the multivariate analysis, body mass index was an independent predictor of difficult DS. Using a body mass index of 31 kg/m2 as a cut-off value, the sensitivity of predicting difficult DS was 73%, and the specificity was 88%. Using a body mass index of 35 kg/m2 as a cut-off value, the specificity increased to 97%, with a sensitivity of 36%.

In patients with a higher body mass index who undergo MitraClip® procedures, DS might be difficult to perform.