Background: Percutaneous mitral valve repair (PMVr) is an established therapy option for high risk patients with severe mitral regurgitation (MR). The procedure is usually conducted under general anesthesia and with guidance of fluoroscopy and transesophageal echocardiography (TEE). Positioning of the clip and the potential need for further clips depends on the intraprocedural evaluation of MR severity. Hence, an intraprocedural precise quantification of MR severity is crucial. It is known that general anesthesia and mechanical ventilation influence the evaluation of MR severity in surgical patients undergoing operative mitral valve repair. However, these effects on the cohort of patients undergoing PMVr are not yet investigated. 

 

Aim: This study sought to compare MR severity assessed at preprocedural diagnostic work-up by TEE under sedation with midazolam with intraprocedural measurements performed under general anesthesia during PMVr.

 

Methods: We included 25 consecutive patients (age 77±6 years) with secondary MR who underwent PMVr using the MitraClip device. TEE was performed at preprocedural work-up and during the procedure. Preprocedural TEE was performed under conscious sedation with midazolam (range from 1 to 5 mg), whereas PMVr was conducted under general anesthesia through continuous infusion of propofol and remifentanil. Assessment of MR severity was based on measurements of color-Doppler jet area (CJA), vena contracta (VC), effective regurgitation orifice area (EROA) and regurgitant volume (RVOL). MR severity was graded as mild, moderate or severe based on EROA and RVOL measurements.

 

Results: Preprocedural CJA was larger than during the procedure (11.7±4.4 vs. 9.9±4.3 cm²; p<0.0001) suggesting that general anesthesia influences this parameter of MR. VC was not different before and during the procedure (5.1±1.4 vs. 4.8±1.7 mm; p=0.2433). EROA (30.9±11.5 vs. 25.2±11.1 mm²; p<0.0001) as well as RVOL (44.4±14.2 vs. 37.5±13.8 ml/beat; p<0.0001) were considerably larger in preprocedural work-up compared to assessment under general anesthesia during PMVr. 

Looking at preprocedural MR severity grade 23 patients (92%) were categorized as severe and 2 patients (8%) as moderate. Under general anesthesia there was a significant number of patients with change of MR severity grade and only 15 patients (60%) were categorized as severe and 10 patients (40%) as moderate (p=0.0078) (Figure 1).

 

Conclusions: General anesthesia affects assessment of MR and leads to a markedly reduction of regurgitation severity. Underestimation of baseline MR severity under general anesthesia must be considered when procedural success is assessed during PMVr.