M. Boodhwani

Centrifugal Pump and Roller Pump in Adult Cardiac Surgery: A Meta‐Analysis of Randomized Controlled Trials

Centrifugal pump (CP) and roller pump (RP) designs are the dominant main arterial pumps used in cardiopulmonary bypass (CPB). Trials reporting clinical outcome measures comparing CP and RP are controversial. Therefore, a meta-analysis was undertaken to evaluate clinical variables from randomized controlled trials (RCTs). Keyword searches were performed on Medline (1966-2011), EmBase (1980-2011), and CINAHL (1981-2011) for studies comparing RP and CP as the main arterial pump in adult CPB. Pooled fixed-effects estimates for dichotomous and continuous data were calculated as an odds ratio and weighted-mean difference, respectively. The P value was utilized to assess statistical significance (P < 0.05) between CP and RP groups. Eighteen RCTs met inclusion criteria, which represented 1868 patients (CP = 961, RP = 907). The prevailing operation was isolated coronary artery bypass graft surgery (CP = 88%, RP = 87%). Fixed-effects pooled estimates were performed for end-of-CPB (ECP) and postoperative day one (PDO) for platelet count (ECP: P = 0.51, PDO: P = 0.16), plasma free hemoglobin (ECP: P = 0.36, PDO: P = 0.24), white blood cell count (ECP: P = 0.21, PDO: P = 0.66), and hematocrit (ECP: P = 0.06, PDO: P = 0.51). No difference was demonstrated for postoperative blood loss (P = 0.65) or red blood cell transfusion (P = 0.71). Intensive care unit length of stay (P = 0.30), hospital length of stay (P = 0.33), and mortality (P = 0.91) were similar between the CP and RP groups. Neurologic outcomes were not amenable to pooled analysis; nevertheless, the results were inconclusive. There was no reported pump-related malfunction or mishap. The meta-analysis of RCTs comparing CP and RP in adult cardiac surgery suggests no significant difference for hematological variables, postoperative blood loss, transfusions, neurological outcomes, or mortality.

EVOLUTION OF LEFT VENTRICULAR HYPERTROPHY IN AORTIC VALVE REPLACEMENT PATIENTS: A LONGITUDINAL ANALYSIS OF 639 PATIENTS

BACKGROUND: Aortic valve disease causes left ventricular hypertrophy (LVH) due to pressure and/or volume overload. Although survival and quality of life after aortic valve replacement (AVR) have been linked to regression of LVH, remodeling processes and predictors of LV mass regression have not been formally characterized. In this study, we sought to evaluate changes in LV mass index (LVMI) over time after AVR, and identify patientand valve-related factors that affect LVMI regression. METHODS: A total of 639 patients with preoperative LVH were studied longitudinally with follow-up appointments and echocardiography. The mean follow-up was 9.4 8.4months, and we a priori defined Period1 postoperative echocardiograms as performed 0-10 months after surgery, Period2 as 10-20 months, Period3 as 20-30 months. LVMI was obtained by indexing LV mass to body surface area. LVH was defined as LVMI>116g/m2 in men and LVMI>96 g/m2 in women. Predictors were assessed with multivariate regression analysis. RESULTS: Most of the LV mass regression occurred in Period1 (p<0.04). In Period1, preoperative severity of LVH and age were strong predictors of LVMI regression (p<0.04). Patients over 75 years of age had the lowest percentage of LVMI regression from baseline (8.8%), compared with those aged 18-65 years (22.7%) and aged 65-75 years (15.2%)(p1⁄40.01). Preoperative severity of aortic stenosis (AS) and aortic insufficiency (AI) were also significant predictors of LVMI regression in Period1 (p<0.04); patients with severe preoperative AS had a 15.4% regression from baseline versus 9.7% regression in patients with less-severe AS. Patients with severe AI had 20.2% regression from baseline versus 9.5% regression in patients with less-severe AI. Moreover, patients with a preoperative diagnosis of coronary artery disease (CAD) had 19.8% regression from baseline versus 8.3% in patients without CAD (p<0.01). A higher postoperative aortic valve mean gradient through the aortic prosthesis was inversely associated with LVMI regression during Period1 (by 1.27% per mmHg of mean gradient, p<0.01). CONCLUSION: During Period1, higher preoperative LVMI, age <75 years, more severe AS, more severe AI, preoperative CAD, and/or lower postoperative trans-prosthesis mean gradient correlate with more LVMI regression. This study is the largest longitudinal series of AVR patients followed for LV mass regression. It helps further our understanding of LVMI regression in LVH patients, reinforces physicians’ knowledge of specific follow-up requirements for these patients, and supports future outcome-based and therapeutic research. 148 LONG-TERM OUTCOMES OF AORTIC VALVE REPAIR: A MULTICENTER STUDY