Does a minimally invasive approach increase the incidence of patient-prosthesis mismatch in aortic valve replacement?

BACKGROUND AND AIM OF THE STUDY: The impact of a minimally invasive approach on patient-prosthesis mismatch (PPM) in patients undergoing aortic valve replacement (AVR) remains unknown. The study aim was to identify the impact of a minimally invasive approach for AVR on the incidence of PPM.

METHODS: The results of a single-center experience in 506 patients who underwent isolated AVR through a minimally invasive or conventional sternotomy were analyzed. Postoperative PPM was defined as an effective orifice area index < 0.85 cm2/m2, and was correlated with surgical approach, mortality and cardiac events after surgery.

RESULTS: Overall, postoperative PPM was present in 26.0% of the patients. The ratio of PPM was 24.1% in minimal access patients and 27.7% in conventional AVR patients (p = 0.35). Hospital mortality was similar in both groups (3.8% versus 3.4%, p = 0.62). The body mass index (BMI) was higher in patients with PPM (28.5 +/- 4.4 versus 25.3 +/- 3.6 kg/m2; p = 0.0001), but obesity was significantly associated with PPM (36.3% versus 9.4%; p = 0.0001). The PPM group included more patients with a left ventricular ejection fraction (LVEF) < 0.50 (12.8% versus 5.3%; p = 0.004). The independent risk factors for PPM were increased BMI (p = 0.0001), LVEF < 0.50 (p = 0.007) and preoperative aortic stenosis (p = 0.029). A LVEF < 0.50 increased the risk for PPM by 3.77-fold (95% CI: 1.4-9.9), while a high BMI increased the risk by 1.42-fold (95% CI: 1.3-1.5). Preoperative aortic insufficiency was associated with PPM, but did not significantly increase the risk.

CONCLUSION: A minimally invasive approach for AVR did not lead to an increased incidence of PPM and associated adverse events following surgery.