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.

Mortality risk prediction in coronary surgery: a locally developed model outperforms external risk models.

This study aimed at assessing the performance of three external risk-adjusted models - logistic EuroSCORE, Parsonnet score and Ontario Province Risk (OPR) score - in predicting in-hospital mortality in patients submitted to coronary artery bypass graft (CABG) and to develop a local risk-score model. Data on 4567 patients who underwent isolated CABG (1992-2001) were extracted from our clinical database. Hospital mortality was 0.96% (44 patients). For the three external systems, observed and predicted mortalities were compared, and discrimination and calibration were assessed. A local risk model was developed and validated by means of logistic regression and bootstrap analysis. The EuroSCORE predicted a mortality of 2.34% (P<0.001 vs. observed), the Parsonnet 4.43% (P<0.0001) and the OPR 1.66% (P<0.005). All models overestimated mortality significantly in almost all tertile risk groups. The areas under the ROC curve (AUC) for EuroSCORE, Parsonnet and OPR were 0.754, 0.664 and 0.683, respectively. The local model exhibited good calibration and discrimination AUC, 0.752. In conclusion, the three risk-score systems analyzed do not accurately predict in-hospital mortality in our coronary surgery patients; hence their use for risk prediction may not be appropriate in our population. We developed a risk-prediction model that can be used as an instrument to provide accurate information about the risk of in-hospital mortality in our patient population.

Left ventricular aneurysms: early and long-term results of two types of repair.

OBJECTIVE: Controversy still exists regarding the optimal surgical technique for postinfarction left ventricular (LV) aneurysm repair. We analyze the efficacy of two established techniques, linear vs. patch remodeling, for repair of dyskinetic LV aneurysms. METHODS: Between May 1988 and December 2001, 110 consecutive patients underwent repair of LV aneurysms. These represent 2.0% of a total group of 5429 patients who underwent isolated CABG during the period. Seventy-six (69.1%) patients were submitted to linear repair and 34 (30.9%) to patch remodelling. There were 94 (84.5%) men and 17 women, with a mean age of 59.2+/-9.2 years. Coronary surgery was performed in all patients (mean no. of grafts/patient, 2.7+/-0.8) and 14 (12.7%) had associated coronary endarterectomy. Forty-four (40.0%) patients had angina CCS class III/IV (linear 43.4%, patch 32.4%, NS) and the majority was in NYHA class I/II (88.2% in both groups). Left ventricular dysfunction (EF>40%) was present in 72 (65.5%) patients (linear 61.8%, patch 73.5%, NS). RESULTS: There was no perioperative mortality, and major morbidity was not significantly different between linear repair and patch repair groups. During a mean follow-up of 7.3+/-3.4 years (range 4-182 months) 14 patients (14.3%) had died, 12 (85.7%) of possible cardiac-related cause. Actual global survival rate was 85.7%. Actuarial survival rates at 5, 10 and 15 years were 91.3, 81.4 and 74%, respectively. There was no significant difference in late survival between the patch and the linear groups. At late follow-up the mean angina and NYHA class were, 1.3 (preoperative 2.4, P<0.001) and 1.5 (preoperative 1.7, NS), respectively, with no difference between the groups. There was no significant difference in hospital readmissions for cardiac causes (linear 22.8% and patch 37.0%). CONCLUSIONS: The technique of repair of postinfarction dyskinetic LV aneurysms should be adapted in each patient to the cavity size and shape, and the dimension of the scar. Both techniques achieved good results with respect to perioperative mortality, late functional status and survival.

Nontransplant surgical options for congestive heart failure.

Although advanced heart failure has been considered the main indication for heart transplantation, the increasing number of candidates and shortage of organs for transplantation, with accumulating waiting lists, has originated another look into more conventional surgery, previously considered of prohibitive risk. In fact, many cases are a result of anatomic lesions that can be corrected by conventional surgery, and in the past decade many surgical groups have obtained good and even excellent results in the treatment of aortic stenosis with low output, and in aortic and mitral regurgitation with severe left ventricular (LV) dysfunction. Also, ischemic and idiopathic dilated cardiomyopathy have been successfully treated by several types of LV remodeling surgery, with or without coronary grafting. Many of these procedures achieved excellent operative, medium-, and long-term results and survival, which match well those observed with cardiac transplantation, most often with advantages in the quality of life and, not unimportantly, in financial costs. For operated patients, especially those with ischemic cardiomyopathy, close follow-up for cardiac failure is extremely important in order to detect the right moment for heart transplantation, if it becomes necessary.

Renal dysfunction after myocardial revascularization.

OBJECTIVES: In this study, we evaluate the incidence of and analyse the pre and intraoperative risk factors for the development of postoperative renal dysfunction (PRD), and the impact of such an event on perioperative mortality and on hospital length of stay. In addition, we sought to investigate the influence of a mildly increased serum creatinine (1.3-2.0 mg/dl) on perioperative mortality and morbidity. METHODS: The study included 2445 consecutive patients who had no pre-existing renal disease (creatinine or=2.1 mg/dl with a preoperative-to-postoperative increase >or=0.9 mg/dl. Univariate and multivariate analyses were performed where appropriate. RESULTS: Global 30-day mortality was 0.7%. The incidence of PRD was 5.6% (136 patients). Mortality for patients who experienced PRD was 8.8 vs. 0.1% for patients who did not (P<0.001). PRD increased the length of hospital stay by 3.4 days (7.6 vs. 11.0 days; P<0.001), and patients who needed haemodialysis (11%) had a perioperative mortality of 33.3% and a mean hospital length of stay of 16 days. Multivariable logistic regression identified the following variables as independent predictors of PRD: age (P=0.017; odds ratio (OR) 1.3 per 10 years), angina class III/IV (P=0.003; OR 1.7); cardiopulmonary bypass time (P=0.007; OR 1.01 per minute); preoperative serum creatinine levels: group 1 (1.3-1.6 mg/dl (P<0.001; OR 5.5)) and group 2 (1.7-2.0 mg/dl (P<0.001; OR 14.2)). Finally, a mild elevation of the preoperative creatinine level (1.3-2.0 mg/dl) increased significantly the probability of perioperative mortality, low cardiac output, haemodialysis and prolonged hospital stay. CONCLUSIONS: Although the likelihood of PRD in patients without pre-existing renal dysfunction is relatively low, it dramatically increases mortality, morbidity and length of stay after CABG. Mildly elevated (>1.2 mg/dl) preoperative serum creatinine level significantly increases the perioperative mortality and morbidity.

Open mitral commissurotomy: the 'golden standard'.

BACKGROUND AND AIM OF THE STUDY: Percutaneous balloon mitral commissurotomy (PBMC) has recently emerged as an alternative to surgical commissurotomy for the treatment of rheumatic mitral valve stenosis. However, this blind procedure may result in incomplete separation of the commissures, which could lead to accelerated restenosis. Hence, open mitral commissurotomy (OMC), which is a visually oriented procedure, remains our method of choice. This study was aimed at assessing the long-term outcome of the OMC procedure. METHODS: A series of OMC performed between 1988 and 1991, involving 100 mitral valves, each with a preoperative echocardiographic score < or =10 was investigated clinically and by echocardiography. RESULTS: Postoperatively, the mean valve area achieved was 2.89+/-0.49 cm2, compared with a mean preoperative value of 0.99+/-0.23 cm2. In a recent follow up, conducted after a mean of 8.5 years (range: 7-11 years), the mean valve area measured by echo-Doppler in this patient group was 2.37+/-0.42 cm2 (range: 1.6 - 3.6 cm2), and 81% of patients had a valve area >2.0 cm2. Reoperation was required in only two cases. The late mortality rate was 4% (0.5%/pt-yr), and was in no case valve-related. Two-thirds of the patients had no or only mild mitral insufficiency, and 93% were in NYHA functional class I or II. The nine-year actuarial survival rate was 96%, freedom from reoperation 98%, and freedom from all valve-related complications 92%. Complementary to this experience, during the past 10 years we have performed modified OMC in 919 (79%) of all 1,151 patients with mitral stenosis submitted for surgery, including 257 with mixed disease. The mean post-commissurotomy valve area (2.9 cm2) was identical to that of the study group. Moderate to severe valve calcification was not an absolute contraindication to valve conservation. CONCLUSION: OMC remains the best alternative for the treatment of all cases of mitral stenosis, independently of the degree of pliability. In our experience, the medium- and long-term results are significantly better than those usually reported in PBMC series.

Non-cardioplegic coronary surgery in patients with severe left ventricular dysfunction.

OBJECTIVES: Although most surgeons use cardioplegia for myocardial protection during coronary artery bypass grafting (CABG), some still use non-cardioplegic methods with very good early and long-term outcome. However, the results in patients with severe left ventricular dysfunction remain unproved. This study evaluates the perioperative mortality and morbidity in patients with severe left ventricular dysfunction submitted to CABG using non-cardioplegic methods. METHODS: From April 1990 through December 1997, 3,180 patients were consecutively subjected to isolated CABG using non-cardioplegic methods, for construction of the distal anastomoses. This prospective study is based on the 107 (3.4%) patients with severe impairment of the left ventricular function (ejection fraction < 30%). The mean age at operation was 57.0 +/- 9.2 years and 95.3% of patients were male. Fifty three patients (49.5%) were in class CCS III/IV and 12 (11.2%) were subjected to urgent surgery. A history of previous myocardial infarction was recorded in 99 (92.5%) patients. Ninety seven (90.6%) patients had triple vessel and 17 (15.9%) left main stem disease, and 77 (71.9%) had a left ventricular end-diastolic pressure > 20 mmHg. Cardiopulmonary bypass time was 73.1 +/- 21.7 min. The mean number of grafts per patient was 3.2. At least one internal mammary artery was used in all cases and 16 patients (14.9%) had bilateral internal mammary artery grafts (1.2 arterial grafts/patient). Endarterectomies were performed in 23 (21.5%) patients. RESULTS: Perioperative mortality was 2.8% (respiratory-1; cardiac-2). Forty one (38.3%) patients required inotropes, but for longer than 24 h in only 12 (11.2%), and two (1.9%) needed intra-aortic counterpulsation. The incidence of myocardial infarction was 2.8%. Two (1.9%) patients had reintervention for haemorrhage and another five (4.6%) for sternal complications. The incidences of supraventricular arrhythmias, renal failure and cerebrovascular accident were 16.8%, 3.6% and 2.8%, respectively. The mean time of hospital stay was 9.3 +/- 6.4 days. CONCLUSION: These results appear to demonstrate that non-cardioplegic methods afford good myocardial protection and operating conditions with excellent applicability, even in patients with severe left ventricular dysfunction.