Propensity score analysis of outcomes following minimal access versus conventional aortic valve replacement

Minimal access aortic valve replacement has become routine in many institutions. Aim of this study was to compare the clinical outcomes between conventional and minimal access aortic valve replacement.

We retrospectively analysed the data of 2103 patients who underwent primary, isolated aortic valve replacement (AVR) in our institution between January 2001 and May 2012 with a minimal access AVR (MAAVR) via the upper partial ministernotomy approach (n = 936) or conventional AVR (CAVR) via the full sternotomy approach (n = 1167). After propensity score matching considering potential confounders [age, sex (female), weight, height, preoperative serum creatinine level, previous myocardial infarction, LV-EF and aortic valve pathology (isolated AS)], 585 matched patients were included in each group.

Mean age (65 ± 10.5 vs 65.7 ± 11.5 years, P = 0.23), gender (females 37.2%, P = 0.9), aortic cross-clamp time (65.6 ± 18.4 vs 64.3 ± 19.8 min, P = 0.25) and postoperative blood loss [median (IQR) 400 (224-683) vs 400 (250-610) ml, P = 0.83) were similar in MAAVR and CAVR group. Thirty-day mortality was also not significantly different (1.5 vs 1.7%, P = 0.74, respectively). In contrast, CPB times were significantly longer in MAAVR (93.5 ± 25 vs 88 ± 28 min, P < 0.001). Intraoperative and postoperative autologous blood transfusions were significantly lower in MAAVR (927.2 ± 425.6 vs 1036.4 ± 599.6 ml, P < 0.001 and 170.2 ± 47.6 vs 243.5 ± 89.3 ml, P < 0.001, respectively). Intubation time was significantly shorter in MAAVR [median (IQR) 7 (5-11) vs 8 (6-14) h, P = 0.01). The incidence of renal insufficiency (creatinine ≥1.5 mg/dl) and respiratory insufficiency (need for non-invasive ventilation, reintubation or tracheotomy) was significantly lower in MAAVR (9 vs 16%, P < 0.001 and 8.5 vs 11.8%, P = 0.03, respectively).

In comparison with CAVR, our study shows that MAAVR is a safe and effective procedure associated with low mortality rate and good long-term survival rates. In addition to that, MAAVR was associated with shorter ventilation times, lower rate of autologous blood transfusion, as well as a lower rate of postoperative respiratory and renal insufficiency. Because of the superior cosmetic results, we therefore advocate MAAVR as the procedure of choice for primary isolated AVR.