Diem Thi Thuy Dinh

Impact of prosthesis–patient mismatch after mitral valve replacement: a multicentre analysis of early outcomes and mid-term survival

Background Prosthesis–patient mismatch (PPM) is characterised by the effects of inadequate prosthesis size relative to body surface area (BSA). It is uncertain whether PPM after mitral valve replacement impacts upon clinical outcome. This was examined in an Australian population. Methods From 2001 to 2009, 1006 mechanical and bioprosthetic mitral valves were implanted across 10 institutions. Effective orifice areas (EOA) were obtained from a literature review of in vivo echocardiographic data. Absent, moderate and severe PPM was defined as an indexed EOA (EOA/BSA) of >1.20u2005cm2/m2, >0.90 to ≤1.20u2005cm2/m2 and ≤0.9u2005cm2/m2, respectively. Early outcomes and 7-year survival were compared between these three groups. Results PPM was absent in 34%, moderate in 53% and severe in 13% of patients. Patients with PPM were more likely to be male (42% vs 52% vs 62%, p<0.0001) and obese (14% vs 20% vs 56%, p<0.0001). Postoperatively there was similar 30-day mortality (5% vs 5% vs 6%, p=0.83) and early any mortality/morbidity (24% vs 27% vs 29%, p=0.40). Seven-year survival was similar between groups (72±4.1% vs 76±3.2% vs 69±10.3%, p=0.76). PPM did not predict adverse events after logistic and Cox regressions with and without propensity score adjustment. Subgroup analyses of those with isolated mitral valve surgery, patients with preoperative congestive heart failure and non-obese patients failed to show an association between PPM and mid-term mortality. Conclusions Overall, PPM was not associated with poorer early outcomes or mid-term survival. Oversizing valves may be technically hazardous and do not yield superior outcomes. Easier implantation by appropriate sizing appears justified.

Impact of left ventricular dysfunction on early and late outcomes in patients undergoing concomitant aortic valve replacement and coronary artery bypass graft surgery

BACKGROUNDnAn increasing proportion of patients present for concomitant aortic valve replacement (AVR) and coronary artery bypass grafting (CABG) with left ventricular (LV) dysfunction. The aim of this study was to evaluate the early outcomes and late survival of patients with different degrees of LV function undergoing concomitant AVR and CABG.nnnMETHODSnBetween June 2001 and December 2009, patients undergoing concomitant AVR-CABG were identified from the Australian and New Zealand Society of Cardiac and Thoracic Surgeons Cardiac Surgery Database Program. Demographic, operative data and post-operative outcomes were compared between patients with normal (> 60%), moderately impaired (30- -60%), and severely impaired (< 30%) estimated LV ejection fraction (LVEF). Independent risk factors for short- and long-term mortality were identified using binary logistic and Cox regression, respectively.nnnRESULTSnAVR-CABG was performed in 2,563 patients with a mean follow up of 36 months (range 0-106). 144 (5.6%) had severely impaired LVEF, 983 (38.3%) had moderately impaired LVEF while the remaining 1377 (53.7%) had normal LVEF. The 30-day mortality in patients with severely impaired, moderately impaired and normal LVEF was 9.0%, 4.3% and 2.9%, respectively. This was significant on univariate (p < 0.001) but not multivariate analysis (p = NS). Severely impaired, moderately impaired and normal LVEF patients experienced 5-year survivals of 63.7%, 77.1% and 82.5%, respectively. Severely impaired LVEF was an independent multivariable predictor of late mortality (HR 1.71; 95% CI 1.22-2.40; p = 0.002).nnnCONCLUSIONSnPatients with severely impaired LVEF experience worse outcomes. However, in the era of modern surgery, this alone should not predicate exclusion, given the established benefits of surgery in this high-risk group.

A propensity-score matched analysis on the impact of postoperative atrial fibrillation on the early and late outcomes after concomitant aortic valve replacement and coronary artery bypass graft surgery

Background Postoperative atrial fibrillation (POAF) is a known complication of cardiac surgery. There is a paucity of data on the effects of POAF on short-term and long-term outcomes after concomitant aortic valve replacement and coronary artery bypass grafting (AVR–CABG ). Methods We retrospectively reviewed data on patients without preexisting arrhythmia who underwent isolated first-time AVR–CABG between June 2001 and December 2009 using the Australasian Society of Cardiac and Thoracic Surgeons National Cardiac Surgery Database Program. Preoperative characteristics, early postoperative outcomes and late survival were compared between patients who developed POAF and those who did not. Propensity score matching was performed to account for the differences between the two groups. Results Isolated AVR–CABG surgery was performed in 2028 patients without preexisting arrhythmias at 18 Australian institutions, of whom 894 (44.1%) developed POAF. POAF patients were generally older (mean age, 75 vs. 73 years, Pu200a<u200a0.001). From the initial study population, 715 propensity-matched patient-pairs were derived; the overall matching rate was 80.0%. In the matched groups, 30-day mortality was similar in both groups (3.5 vs. 2.1%, Pu200a=u200a0.16). Patients with POAF, however, were more likely to develop perioperative complications, including new renal failure, prolonged ventilation (>24u200ah), multisystem failure and readmission within 30 days of surgery (all Pu200a<u200a0.05). Patients with POAF also had a significantly greater length of hospital stay (Pu200a<u200a0.001). Seven-year survival was not significantly different between the two groups (72 vs. 75%, Pu200a=u200a0.11). Conclusion POAF was not associated with an increased risk of early or late mortality. It is, however, associated with poorer perioperative outcomes. It is important to evaluate potential treatment strategies for POAF.

PROGNOSTIC VALUE OF THE MAYO CLINIC RISK SCORE FOR CORONARY ARTERY REVASCULARIZATION USING THE AUSTRALASIAN SOCIETY OF CARDIAC AND THORACIC SURGEONS AND THE MELBOURNE INTERVENTIONAL GROUP REGISTRIES

Authors: Bryan P. Yan, Cheng-Hon Yap, Nick Andrianopoulos, Thomas J. Kiernan, Andrew E. Ajani, Julian A. Smith, David J. Clark, Stephen J. Duffy, Gilbert C. Shardey, Angela L. Brennan, Diem T. Dinh, Christopher M. Reid, Bernard J. Gersh, Australasian Society of Cardiac and Thoracic Surgeons and Melbourne Interventional Group, Chinese University of Hong Kong, Hong Kong, Hong Kong, Monash University, Melbourne, Australia