Pedro E. Antunes

Risk-prediction for postoperative major morbidity in coronary surgery

OBJECTIVE Analysis of major perioperative morbidity has become an important factor in assessment of quality of patient care. We have conducted a prospective study of a large population of patients undergoing coronary artery bypass surgery (CABG), to identify preoperative risk factors and to develop and validate risk-prediction models for peri- and postoperative morbidity. METHODS Data on 4567 patients who underwent isolated CABG surgery over a 10-year period were extracted from our clinical database. Five postoperative major morbidity complications (cerebrovascular accident, mediastinitis, acute renal failure, cardiovascular failure and respiratory failure) were analysed. A composite morbidity outcome (presence of two or more major morbidities) was also analysed. For each one of these endpoints a risk model was developed and validated by logistic regression and bootstrap analysis. Discrimination and calibration were assessed using the under the receiver operating characteristic (ROC) curve area and the Hosmer-Lemeshow (H-L) test, respectively. RESULTS Hospital mortality and major composite morbidity were 1.0% and 9.0%, respectively. Specific major morbidity rates were: cerebrovascular accident (2.5%), mediastinitis (1.2%), acute renal failure (5.6%), cardiovascular failure (5.6%) and respiratory failure (0.9%). The risk models developed have acceptable discriminatory power (under the ROC curve area for cerebrovascular accident [0.715], mediastinitis [0.696], acute renal failure [0.778], cardiovascular failure [0.710], respiratory failure [0.787] and composite morbidity [0.701]). The results of the H-L test showed that these models predict accurately, both on average and across the ranges of patient deciles of risk. CONCLUSIONS We developed a set of risk-prediction models that can be used as an instrument to provide information to clinicians and patients about the risk of postoperative major morbidity in our patient population undergoing isolated CABG.

Coronary surgery in patients with diabetes mellitus: a risk-adjusted study on early outcome

OBJECTIVES We aimed at determining the effect of diabetes mellitus (diabetes) on short-term mortality and morbidity in a cohort of patients with ischemic disease undergoing coronary artery bypass surgery (CABG) at our institution. MATERIAL AND METHODS A total of 4567 patients undergoing isolated CABG in a 10-year period were studied. Diabetes mellitus was present in 22.6% of the cases but the percentage increased from 19.1% in the beginning to 27% in the end of the study period (p<0.0001 for the decade time-trend). Compared with non-diabetic patients, the group with diabetes was older (61.5+/-8.4 years vs 60.4+/-9.5 years), had a higher body mass index (26.4+/-2.2 vs 26.0+/-2.2), comprised more women (17.5% vs 10.1%), and had a greater incidence of peripheral vascular disease (13.3% vs 8.8%), cerebrovascular disease (8.3% vs 4.3%), renal failure (2.7% vs 1.1%), cardiomegaly (14.0% vs 10.9%), class III-IV angina (43.4% vs 39.0%), triple-vessel disease (80.9% vs 73.7%) and patients with left ventricular dysfunction (all p<0.05). Demographic and peri-procedural data were registered prospectively in a computerized institutional database. Multivariate logistic regression was performed to assess the influence of diabetes as an independent risk factor for in-hospital mortality and morbidity. RESULTS The overall in-hospital mortality was 0.96% [n=44; diabetics: 1.0%, non-diabetics: 0.9% (p=0.74)]. The mortality of patients with diabetes decreased from 2.7% in the early period to 0.7% in the late period (p=0.03 for the time-trend). Postoperative in-hospital complications were comparable in the two groups in univariate analysis, with only cerebrovascular accident and prolonged length of stay being significantly higher in the diabetic patients (all p<0.05). In multivariate analysis, diabetes was not found to be an independent risk factor for in-hospital mortality (OR=0.61; 95% CI=0.28-1.30; p=0.19), but predicted the occurrence of mediastinitis (OR=1.80; 95% CI=1.01-3.22; p=0.049). CONCLUSIONS Despite worse demographic and clinical characteristics, diabetic patients could be surgically revascularized with low mortality and morbidity, comparable with control patients. Hence, our data do not support diabetes as a risk factor for significantly adverse early outcome following CABG.

Coronary surgery with non-cardioplegic methods in patients with advanced left ventricular dysfunction: immediate and long term results

Objective: To evaluate perioperative results and long term survival in patients with severe left ventricular (LV) dysfunction undergoing coronary artery bypass grafting (CABG) using non-cardioplegic methods. Methods: From April 1990 through December 1999, 4100 consecutive patients underwent isolated CABG using hypothermic ventricular fibrillation. Of these, 141 (3.4%) had severe LV dysfunction (ejection fraction < 30%). Mean age was 58.3 (9.6) years. 64 patients (45.4%) were in Canadian Cardiovascular Society class III or IV and 16 (11.3%) were subjected to urgent or emergent surgery. A previous myocardial infarction was recorded in 127 (90.1%). The majority (89.4%) had triple vessel and 26 (18.4%) had left main disease. The mean number of grafts per patient was 3.1. At least one internal thoracic artery was used in all patients and 21 (14.8%) had bilateral internal thoracic artery grafts (1.2 arterial grafts per patient). Results: Perioperative mortality was 2.8% (4 patients) and the incidence of acute myocardial infarction 2.8%. 50 (35.5%) patients required inotropes but only 16 (11.3%) required it for longer than 24 hours; 5 patients (3.5%) needed mechanical support. The incidence of renal failure was 3.5%. Mean duration of hospital stay was 9.6 (8.3) days. Follow up was 95% complete and extended for a mean of 57 (30) months. Late mortality was 11.5%. Actuarial survival rates at 1, 3, and 5 years were 96%, 91%, and 86%, respectively. Conclusions: Non-cardioplegic techniques are safe and effective in preserving the myocardium during CABG in patients with coronary artery disease and poor LV function, with low operative mortality and morbidity, and encouraging medium to long term survival rates.

Donor Mitral Valve Repair in Cardiac Transplantation

INTRODUCTION For many patients suffering from end-stage heart failure, heart transplantation remains the only hope for survival, but the shortage of donor organ is increasing. The growing number of patients awaiting heart transplantation has led many centers to expand the donor pool by liberalizing donor criteria, including advances in surgical techniques on the donor heart, such as valve repair. PATIENTS AND RESULTS We subjected 4 donor hearts to bench repair of the mitral valve. The first heart was from a 35-year-old woman whose echocardiogram showed mild to moderate sclerotic leaflets. We performed a posteromedial commissurotomy and posterior annuloplasty. Transthoracic echocardiography at 57 months after transplantation demonstrated mild mitral regurgitation and no enlargement of VE. The second organ was from a 17-year-old woman with no history of heart disease and an echocardiogram that showed evidence of slightly sclerotic leaflets and mild mitral regurgitation. We performed a posterior annuloplasty. Echocardiography at 12 months demonstrated minimal mitral regurgitation. The third heart was from a 28-year-old woman with a normal echocardiogram. After harvesting, we found a torn head of the posterior papillary muscle, which was reimplanted. Two weeks later, the echocardiogram showed no mitral regurgitation. The fourth was from a 47-year-old woman with no history of heart disease and a normal echocardiogram. Examination before implantation showed central insufficiency, for which we performed posterior annuloplasty. Echocardiography at 12 months showed no mitral regurgitation. CONCLUSION An aggressive approach to use hearts from marginal donors expands the pool and decreases waiting time for patients who desire heart transplantation.

Left-ventricular aneurysms: from disease to repair

Myocardial infarction may be complicated by the formation of a left-ventricular aneurysm that distorts the normal elliptical geometry of the ventricle to produce a dilated spherical ventricle with limited contractile and filling capacities. One of the consequences is congestive heart failure, which may be refractory to medical therapy and require surgical treatment. Surgical methods to restore the volume and shape of the left ventricle have evolved over the years. Nevertheless, although surgery for left-ventricular aneurysms has been performed for almost 50 years, the most appropriate approach is still controversial. This review gives an overview of the postinfarction left-ventricular aneurysm, tackling issues from the disease itself to surgical and other techniques of ventricular remodeling.

Long-term follow-up of elderly patients subjected to aortic valve replacement with mechanical prostheses.

We propose to analyse the long-term follow-up in patients older than 65 years of age who received a mechanical valve in the aortic position, using death and prosthetic-related complications as endpoints. From April 1988 to December 1995, 144 consecutive patients 65-75 years of age (mean 67.7+/-2.5) were enrolled. Total duration of follow-up was 1663 patient-years (median 13.0 years) and was complete for 99% of the patients. Thirty-day mortality was 1.4% (n=2). At the end of the study, 77 patients (53.8%) were alive, with ages ranging from 77 to 91 years (mean 82.1+/-3.2 years). The overall 5-, 10- and 15-year actuarial survival was 87.4%+/-3.0, 67.7%+/-4.3 and 58.5%+/-4.5, respectively. Freedom from stroke was 93.3+/-3.1%, 84.6+/-3.3% and 71.7+/-4.5%, respectively, after identical periods. Freedom from major bleeding was 97.2+/-1.1%, 90.4+/-3.5% and 86.4+/-4.0%, respectively. Freedom from endocarditis was 95.7+/-2.3%, 95.0+/-2.1% and 94.4+/-2.5%, respectively, and freedom from reoperation was 98.0+/-1.2%, 97.6+/-1.3%, 96.9+/-2.4% and 96.4+/-2.6%, respectively. Freedom from major valve-related events was 87.7+/-2.6%, 73.9+/-3.4% and 61.5+/-4.6%, respectively. Nearly two-thirds of the patients were alive and free from major adverse valve-related events. Hence, we consider implantation of a mechanical prosthesis in elderly patients safe and appropriate, but the choice must be tailored for each specific patient.

Coronary artery bypass surgery without cardioplegia: hospital results in 8515 patients

OBJECTIVES Cardioplegic myocardial protection is used in most cardiac surgical procedures. However, other alternatives have proved useful. We analysed the perioperative results in a large series of patients undergoing coronary artery bypass (CABG) using cardiopulmonary bypass (CPB) and non-cardioplegic methods. METHODS From January 1992 to October 2013, 8515 consecutive patients underwent isolated CABG with CPB without cardioplegia, under hypothermic ventricular fibrillation and/or an empty beating heart. The mean age was 61.9 ± 9.5 years, 12.4% were women, 26.3% diabetic, 64% hypertensive; and 9.6% had peripheral vascular disease, 7.8% cerebrovascular disease and 54.3% previous acute myocardial infarction (AMI). One-third of patients were in Canadian Cardiovascular Society Class III/IV. Three-vessel disease was present in 76.5% of the cases and 10.9% had moderate/severe left ventricle (LV) dysfunction (ejection fraction <40%). A multivariate analysis was made of risk factors associated to in-hospital mortality and three major morbidity complications [cerebrovascular accident, mediastinitis and acute kidney injury (AKI)], as well as for prolonged hospital stay. RESULTS The mean CPB time was 58.2 ± 20.7 min. The mean number of grafts per patient was 2.7 ± 0.8 (arterial: 1.2 ± 0.5). The left internal thoracic artery (ITA) was used in 99.4% of patients and both ITAs in 23.1%. The in-hospital mortality rate was 0.7% (61 patients), inotropic support was required in 6.6% and mechanical support in 0.8, and 2.0% were re-explored for bleeding and 1.3% for sternal complications (mediastinitis, 0.8%). AKI, the majority transient, occurred in 1595 patients (18.9%). The incidence rates of stroke/transient ischemic attack (TIA) and acute myocardial infarction (AMI) were 2.6 and 2.5%, respectively, and atrial fibrillation/flutter occurred in 22.6% of cases. Age, LV dysfunction, non-elective surgery, previous cardiac surgery, peripheral vascular disease and CPB time were independent risk factors for mortality and major morbidity. The mean hospital stay was 7.2 ± 5.7 days. CONCLUSIONS Isolated CABG with CPB using non-cardioplegic methods proved very safe, with low mortality and morbidity. These methods are simple and expeditious and remain as very useful alternative techniques of myocardial preservation.

Aortic valve surgery in patients who had undergone surgical myocardial revascularization previously

OBJECTIVES A very high percentage of patients submitted to coronary artery bypass grafting (CABG) develop symptomatic aortic disease requiring surgery upon ageing. The surgical risk of the redo procedure is controversial. We describe our recent experience with patients submitted to this surgery under such conditions. METHODS From July 1999 to July 2010, 51 patients (mean age, 70.3 ± 7.0 years, 86.3% male) submitted to CABG previously required aortic valve surgery (AVS). The mean interval between the surgeries was 7.1 ± 3.9 years. Twenty-one patients (41.2%) had also undergone AVS during the first surgery [12 patients (57.7%) had valve replacement and 9 patients (42.8%) had valvuloplasty]. At presentation, 51.0% were in New York Heart Association Class III/IV and the standard and logistic EuroSCOREs were 10.1 ± 2.5 and 20.9 ± 16.5%, respectively. RESULTS Aortic valve replacement was performed in 48 patients (94.1%). Two patients had undergone a surgery for the closure of a peri-prosthetic leak and one patient a valvuloplasty. Thirteen patients (25.5%) needed to undergo additional cardiac procedures, including root enlargement (three patients, 5.9%). Valve surgery was performed with non-dissection of the internal thoracic artery graft, when patented, and antegrade cardioplegic arrest of other territories. Hospital and 30-day mortality rate was 2% (n = 1). The mean duration of hospital stay was 13.0 ± 11.1 days. The most frequent complication was arrhythmias - in 25.5% of the patients, and mostly due to atrial fibrillation (19.6%). Permanent pacemaker for A-V block was required in 5.9% of the cases, stroke was documented in two cases (3.9%) and early re-intervention was observed in two cases. CONCLUSIONS Redo AVS performed in patients submitted to CABG previously results in mortality and morbidity rates that are much lower than what is expected, bringing clear benefits to the patients.

Coronary artery bypass surgery in young adults: excellent perioperative results and long-term survival

OBJECTIVES To analyse perioperative results, long-term survival and freedom from complications after coronary artery bypass grafting (CABG) in young adults. METHODS A total of 163 patients, 40 years old or younger, had isolated CABG from January 1989 to December 2010. Pre- and perioperative demographic and clinical data were retrieved from a prospectively organised database. Follow-up data were obtained by letter or telephone interviews. The mean age of the patients was 37.6 ± 2.9 years and 146 were men (90%). Fifty-three patients (32.5%) had angina class III/IV; 106 (65.0%), previous myocardial infarction; and 23 (14.1%), impaired left ventricular function (ejection fraction <40%). Indication for surgery was 3-vessel disease in 101 cases (62.0%), 2-vessel disease in 30 (18.4%) and single-vessel disease in 32 (19.6%). The left main stem was affected in 16 patients (9.8%). The mean EuroSCORE II was 0.92 ± 0.71. A total of 417 grafts were constructed (mean 2.6 grafts/patient), 247 of which (59.2%) were arterial. RESULTS There were no in-hospital deaths. The mean hospital stay was 7.1 ± 4.0 days. Four patients (2.5%) were lost to follow-up, which extended from 3 to 25 years (mean 15.1 ± 5.5 years). There were 22 late deaths, 72.7% of cardiac or unknown origin. The 5-, 10- and 20-year survival rates were 98.7 ± 10.9, 95.2 ± 1.8 and 79.4 ± 4.4%, respectively. Twenty-six patients (18.1%) had non-fatal cardiac adverse complications (myocardial infarct, percutaneous re-revascularization or class III/IV angina), for 5-, 10- and 20-year freedom from complications of 97.9 ± 1.2, 91.9 ± 2.5 and 65.7 ± 7.1%, respectively. Twenty-two patients (17.5%) needed re-revascularization, for 5-, 10- and 20-year freedom from re-revascularization of 97.6 ± 1.4, 91.9 ± 2.6 and 69.5 ± 6.7%, respectively. CONCLUSIONS Despite the aggressive nature of coronary artery disease in young patients, perioperative death and morbidity rates are low, with good long-term survival and low rates of re-revascularization.OBJECTIVES To analyse perioperative results, long-term survival and freedom from complications after coronary artery bypass grafting (CABG) in young adults. METHODS A total of 163 patients, 40 years old or younger, had isolated CABG from January 1989 to December 2010. Pre- and perioperative demographic and clinical data were retrieved from a prospectively organised database. Follow-up data were obtained by letter or telephone interviews. The mean age of the patients was 37.6 ± 2.9 years and 146 were men (90%). Fifty-three patients (32.5%) had angina class III/IV; 106 (65.0%), previous myocardial infarction; and 23 (14.1%), impaired left ventricular function (ejection fraction <40%). Indication for surgery was 3-vessel disease in 101 cases (62.0%), 2-vessel disease in 30 (18.4%) and single-vessel disease in 32 (19.6%). The left main stem was affected in 16 patients (9.8%). The mean EuroSCORE II was 0.92 ± 0.71. A total of 417 grafts were constructed (mean 2.6 grafts/patient), 247 of which (59.2%) were arterial. RESULTS There were no in-hospital deaths. The mean hospital stay was 7.1 ± 4.0 days. Four patients (2.5%) were lost to follow-up, which extended from 3 to 25 years (mean 15.1 ± 5.5 years). There were 22 late deaths, 72.7% of cardiac or unknown origin. The 5-, 10- and 20-year survival rates were 98.7 ± 10.9, 95.2 ± 1.8 and 79.4 ± 4.4%, respectively. Twenty-six patients (18.1%) had non-fatal cardiac adverse complications (myocardial infarct, percutaneous re-revascularization or class III/IV angina), for 5-, 10- and 20-year freedom from complications of 97.9 ± 1.2, 91.9 ± 2.5 and 65.7 ± 7.1%, respectively. Twenty-two patients (17.5%) needed re-revascularization, for 5-, 10- and 20-year freedom from re-revascularization of 97.6 ± 1.4, 91.9 ± 2.6 and 69.5 ± 6.7%, respectively. CONCLUSIONS Despite the aggressive nature of coronary artery disease in young patients, perioperative death and morbidity rates are low, with good long-term survival and low rates of re-revascularization.

Uma década de transplantação cardíaca em Coimbra. O valor da experiência

INTRODUCTION AND OBJECTIVES To analyze the experience gained in 10 years of the heart transplantation program of the University Hospital of Coimbra. METHODS Between November 2003 and December 2013, 258 patients with a mean age of 53.0±12.7 years (3-72 years) and predominantly male (78%) were transplanted. Over a third of patients had ischemic (37.2%) and 36.4% idiopathic cardiomyopathy. The mean age of donors was 34.4±1.3 years and 195 were male (76%), with gender difference between donor and recipient in 32% of cases and ABO disparity (non-identical groups but compatible) in 18%. Harvest was distant in 59% of cases. In all cases total heart transplantation with bicaval anastomoses, modified at this center, was used. Mean ischemia time was 89.7±35.4 minutes. All patients received induction therapy. RESULTS Early mortality was 4.7% (12 patients) from graft failure and stroke in five patients each, and hyperacute rejection in two. Thirteen patients (5%) required prolonged ventilation, 25 (11.8%) required inotropic support for more than 48 hours, and seven required pacemaker implantation. Mean hospital stay was 15.8±15.3 days (median 12 days). Ninety percent of patients were maintained on triple immunosuppressive therapy including cyclosporine, the remainder receiving tacrolimus. In 23 patients it was necessary to change the immunosuppression protocol due to renal and/or neoplastic complications and humoral rejection. All but two patients have been followed in the Surgical Center. Fifty patients (19.4%) subsequently died from infection (18), cancer (10), vascular (eight), neuropsychiatric (four), cardiac (two) or other causes (eight). Forty-six patients (17.8%) had episodes of cellular rejection (>2 R on the ISHLT classification), eight had humoral rejection (3.1%), and 22 have evidence of graft vascular disease (8.5%). Actuarial survival at 1, 5, and 8 years was 87±2%, 78±3% and 69±4%, respectively. CONCLUSION This 10-year series yielded results equivalent or superior to those of centers with wider and longer experience, and have progressively improved following the introduction of changes prompted by experience. This program has made it possible to raise and maintain the rate of heart transplantation to values above the European average.