A risk model derived from the National Registry of Myocardial Infarction 2 database for predicting mortality after coronary artery bypass grafting during acute myocardial infarction

Predicting the mortality of patients with cardiogenic shock after coronary artery bypass grafting

INTRODUCTION

Cardiogenic shock (CS) is a critical condition and the leading cause of mortality after coronary artery bypass grafting (CABG). To define the risk factors for CS in patients who undergo CABG and create a risk-predictive model is crucial.

METHODS

In this observational study, we retrospectively evaluated consecutive patients who underwent CABG between January 2018 and October 2022 at Beijing Anzhen Hospital. A total of 496 patients were enrolled and categorized into the training (396 cases) and internal test (100 cases) sets. The variables significantly associated with mortality (p < 0.05) were analyzed using logistic regression analyses.

RESULTS

The E/A ratio at admission, postoperative brain natriuretic peptide, postoperative arterial lactate, two or more arrhythmias at the same time after CABG, and carotid artery stenosis at admission were identified as independent prognostic factors for in-hospital mortality after multivariate logistic regression analysis. The CS after CABG score (ACCS) was established and three classes of ACCS, named classes I (ACCS, <20), II (ACCS, 20-30), and III (ACCS, >30), made up the risk model. The ACCS showed better discrimination with an AUROC of 0.937 (95% confidence interval, 0.982-0.892) and calibration with the Hosmer-Lemeshow test (X2 = 5.854 with 8 df; p = 0.664). In addition, tenfold cross-validation demonstrated that the mean misdiagnosis rate was 5.56% and the lowest misdiagnosis rate was 6.38%.

CONCLUSION

The ACCS score represents a risk-predictive model for in-hospital mortality of patients with CS after CABG in acute care settings. Patients identified as class III may have a worse prognosis.

Timing of coronary artery bypass grafting after acute myocardial infarction: does it influence outcomes?

Introduction

The optimal timing of coronary artery bypass grafting (CABG) operations in patients with recent acute myocardial infarction (AMI) remains unclear.

Aim

To assess the influence of timing on post-operative outcomes in patients undergoing CABG following AMI.

Material and methods

In this retrospective analysis 12,224 consecutive patients undergoing CABG were included. 2477 (20.5%) patients had a history of AMI. Based on timing, patients were divided into 3 groups: those operated within 7 days of AMI; those operated after 7 days but within 1 month; and a third group operated after 1 month but within 3 months. The 3 groups were compared in terms of baseline, intra-operative, and post-operative morbidity and mortality. Multivariate analysis was carried out to assess the independent influence of timing of CABG on outcomes.

Results

There was no difference in terms of previous neurological events (p = 0.554), presence of carotid artery disease (p = 0.555), prevalence of hypertension (p = 0.119), diabetes (p = 0.144), hypothyroidism (p = 0.53), chronic obstructive pulmonary disease (p = 0.079), peripheral vascular disease (p = 0.771), and impaired left ventricular function (p = 0.072). On univariate analysis, mortality risk was highest between 1 week and 1 month (p = 0.003). Multivariate analysis showed that the closer the MI and CABG duration, the higher the mortality (co-efficient -0.517; p = 0.019; odds ratio = 0.596; 95% CI: 0.388-0.917).

Conclusions

The duration between MI and CABG has a direct influence on outcomes after CABG. While it is clear that the longer the duration between MI and CABG, the lower the mortality risk, it is however difficult to decide on an exact cut-off time frame.

Current outcomes of off-pump coronary artery bypass grafting: evidence from real world practice

Coronary artery bypass grafting (CABG) can be performed conventionally using cardiopulmonary bypass (CPB) and aortic clamping or on a beating heart (BH) without the use of CPB, the so-called off-pump CABG. Some surgeons, who are proponents of off-pump CABG, preferentially use this technique for the majority of operations, whereas others use it only in certain situations which warrant avoidance of CPB. Ever since the conception of off-pump CABG, the never-ending debate about which technique of CABG is safe and efficacious continues to date. Several randomized controlled trials (RCTs) have been conducted that have either favored on-pump CABG or have failed to show a significant difference in outcomes between the two techniques. However, these RCTs have been fraught with claims that they do not represent the majority of patients undergoing CABG in real world practice. Therefore, assessment of the benefits and drawbacks of each technique through observational and registry studies would be more representative of patients encountered in daily practice. The present review examines various retrospective studies and meta-analyses of observational studies that compare the early and long-term outcomes of off- and on-pump CABG, which assesses their safety and efficacy. Additionally, their outcomes in older patients, females, and those with diabetes mellitus, renal dysfunction, presence of ascending aortic disease, and/or acute coronary syndrome (ACS) have also been discussed separately. The general consensus is that early results of off-pump CABG are comparable to or in some cases better than on-pump CABG. However, on-pump CABG provides a survival benefit in the long term according to a majority of publications in literature.

On-pump beating heart coronary revascularization: Is it valid for emergency revascularization?

BACKGROUND

On-pump beating heart coronary artery bypass grafting (CABG) may be considered as an alternative to the conventional on-pump surgery in patients presenting with acute coronary syndrome requiring emergency revascularization. This study reports our clinical experience and early outcomes with the on-pump beating heart coronary surgery on patients with acute coronary syndrome.

DESIGN AND SETTINGS

A retrospective study conducted from August 2009 to October 2015, in a regional training and research hospital in Turkey.

METHODS

A total of 1432 patients underwent isolated CABG at our institution. A total of 316 of these patients underwent the on-pump beating heart procedure without cardioplegic arrest by the same surgeon.

RESULTS

The time interval from the onset of acute myocardial infarction to CABG was 10 (2.2) hours. The mean number of grafts was 3.0 (0.6). Hospital mortality was 2.9% (9 patients). Twelve patients had low cardiac output syndromes after surgery. Eight of them had renal dysfunction but none of them needed hemodialysis. The mean intensive care unit stay was 3 (2) days and the mean hospital length of stay was 7 (4) days.

CONCLUSION

We think that the on-pump beating heart revascularization technique can be a good choice for emergency CABG of high-risk patients with a multivessel coronary artery disease.

Optimal coronary artery bypass grafting strategy for acute coronary syndrome

OBJECTIVE

Conventional coronary artery bypass grafting (CABG) using cardiopulmonary bypass and cardiac arrest is associated with higher mortality and morbidity rates in acute coronary syndrome (ACS) patients undergoing surgery. Although off-pump CABG (OPCAB) is beneficial for high-risk patients, its efficacy for ACS is unknown, with on-pump beating CABG an adjunctive method. We investigated the effects of OPCAB and on-pump beating CABG for ACS.

METHODS

We evaluated 121 consecutive patients with ACS (91 males, 30 females; mean age 69.5 ± 10.3 years) who underwent CABG since 2000. Seventy-five had unstable angina (UA) and 46 acute myocardial infarction (AMI) [non-ST elevation (NSTEMI): 22, ST elevation (STEMI): 24]. We assessed CABG for acute coronary syndrome under our primary OPCAB strategy, and compared perioperative status between UA and AMI patients.

RESULTS

(1) Sixty-five (87 %) with UA underwent OPCAB, 8 on-pump beating CABG, and 2 conventional CABG. Conversion from OPCAB was seen in 4 patients. In-hospital mortality was 1.3 %. (2) All UA patients who had intra-aortic balloon pumping (IABP) underwent OPCAB. No patients with preoperative IABP experienced conversion from OPCAB. (3) In AMI patients, hospital mortality was higher (8.9 %) and the ratios for OPCAB, on-pump beating CABG, and conventional CABG were 39, 57, and 4 %, respectively. Mortality was exclusively seen in patients with STEMI who underwent conventional CABG.

CONCLUSIONS

OPCAB might have beneficial effects for ACS patients with UA, while IABP was found essential for completing OPCAB. In AMI patients, on-pump beating CABG might be reasonable for avoiding conversion from OPCAB and ischemic perfusion injury.

Off-pump Coronary Artery Bypass is a Safe Option in Patients Presenting as Emergency

Introduction: The applicability of off-pump coronary-artery bypass (OPCAB) in patients who present as emergency remains controversial. Herein, we explore the efficacy and safety of OPCAB in patients who were indicated for emergency surgery. Materials and Methods: Between 2002 and 2007, a total of 282 patients underwent OPCAB, of which 68 were presented as emergency. This cohort (group A) was compared to 68 patients who had traditional on-pump coronary artery bypass grafting (CABG, group B) under emergency indications during the same period of time. Baseline demographics, intraoperative data and postoperative outcomes were analysed. Results: Preoperative demographics were comparable in both groups. Mortality during the first 30 days was comparable in both groups and no stroke occurred in the whole series. Patients in group A had significantly less pulmonary complications (4.4% vs 14.7%, P= 0.04), less ventilation time (30.3 ± 33.6 hours vs 41.5 ± 55.4 hours, P = 0.18) and were less likely to have prolonged ventilation, (19.1% vs 35.3%, P = 0.03). Similarly, OPCAB patients had less postoperative renal-failure/dysfunction (5.9% vs 8.8%, P = 0.51) and required less inotropic support (66.2% vs 88.2%, P = 0.002), bloodtransfusions (23% vs 86.8%, P <0.0001), and atrial- (17.6% vs 35.3%, P = 0.02) or ventricular-pacing (17.6% vs 41.2%, P = 0.002). Although the number of diseased vessels was comparable in both groups, patients in group A received less distal anastomoses. (2.78 ± 1.19 vs 3.41 ± 0.89, P = 0.002). Similarly, complete revascularisation was achieved less frequently in group A (76.5% vs 94.1%, P = 0.004). Conclusion: OPCAB strategy is a safe and efficient in emergency patients with reasonable good short-term postoperative outcomes. Keywords: Cardiac surgery, Coronary artery disease, Off-pump coronary-artery bypass

Timing of nonemergent coronary artery bypass grafting and mortality after non-ST elevation acute coronary syndrome

BACKGROUND

The purpose of this study was to determine the association between time to coronary artery bypass grafting (CABG) and mortality among patients admitted with non-ST elevation acute coronary syndrome (NSTEACS). Patients are increasingly being referred for CABG soon after NSTEACS, although few data exist to guide the optimal timing of bypass surgery.

METHODS

We identified a cohort of all patients who underwent nonemergent CABG within 60 days of hospitalization for NSTEACS in the province of Alberta, Canada, from 2000 to 2004. Time from admission to CABG was categorized as early (2-7 days), intermediate (8-14 days), or late (15-60 days-reference group). The primary outcome was mortality occurring within 30 days of surgery.

RESULTS

Of the total cohort of 1,454 patients, 213 (14.6%) underwent early, 637 (43.8%) underwent intermediate, and 707 (48.6%) underwent late CABG surgery. In the final adjusted model time to CABG was not statistically significant as an independent predictor of short-term mortality. Compared to late CABG, there was a nonsignificant increased risk of mortality for those undergoing early (hazard ratio 2.36, 95% CI 0.72-7.76) and intermediate (hazard ratio 1.68, 95% CI 0.76-3.72) CABG surgery.

CONCLUSIONS

Time from admission to CABG was not associated with an increased risk of short-term mortality. However, there was a trend toward increased mortality with early CABG, and this study does not exclude the presence of a modest risk association between timing of CABG and short-term mortality.

Cost comparison of four revascularisation procedures for the treatment of multivessel coronary artery disease

OBJECTIVE

An economic evaluation was performed, using modelling techniques, to compare 1-year total costs of four revascularisation procedures in patients with multivessel disease: on-pump coronary artery bypass grafting (CABG); off-pump CABG; percutaneous coronary intervention (PCI) with bare-metal stents (BMS); and PCI with drug-eluting stents (DES).

METHODS

Clinical data were derived from four randomised clinical trials comparing CABG versus PCI, as well as from literature reviews. Resource use and unit cost estimates were modelled to reflect current Canadian practice.

RESULTS

This study demonstrated that 1 year after the initial revascularisation, PCI with BMS is the least costly procedure, followed by off-pump CABG, PCI with DES and on-pump CABG. DES became the most costly procedure if 3.5 or more DES were used or if staged PCI was performed.

Timing of bypass surgery in stable patients after acute myocardial infarction

OBJECTIVES

To determine the optimal timing for bypass surgery in stable patients after acute myocardial infarction (MI).

BACKGROUND

Coronary artery bypass graft surgery (CABG) is a proven treatment for coronary artery disease. Because of the hypothesized risk of hemorrhagic transformation, it had become common practice to wait four to six weeks after MI. Recently, improvements in surgical and perioperative management, as well as an increase in pre-CABG in-hospital waiting times and excess burden on health care resources, have pushed surgeons to operate earlier. The optimal timing for a stable patient to undergo CABG after MI is unclear, because there have been no randomized trials to answer this question.

METHODS

The published literature comparing early versus late surgical revascularization procedures in stable post-MI patients was reviewed.

RESULTS

No randomized, prospective trials were found; however, several retrospective studies were identified. Most series examining Q wave MIs showed that mortality is higher in the early stages post-MI and progressively decreases with time post-MI. When studies examined non-Q wave MIs separately, there appeared to be less of a mortality difference between early and late surgical revascularization. There was a large disparity between the definitions of early surgery post-MI among the studies, some as early as 6 h and others up to eight days. Factors that increased mortality include abnormal left ventricular function and urgency of surgery, and some studies found risk models helpful to define increased risk after infarction. The possible increased risk of early surgery may be balanced against the potential for improved remodelling, improved quality of life and decreased hospital stay costs.

CONCLUSIONS

There is a need for a randomized, prospective trial examining the optimal timing for CABG in stable post-MI patients.

Predictors and Outcomes of Coronary Artery Bypass Grafting in ST Elevation Myocardial Infarction

BACKGROUND

Treatment of ST-elevation myocardial infarction has undergone great evolution since introduction of percutaneous coronary intervention (PCI). The purpose was therefore to assess the outcome of patients with ST-elevation myocardial infarction undergoing surgical revascularization with coronary artery bypass grafting (CABG).

METHODS

A total of 138 consecutive patients with ST-elevation myocardial infarction underwent CABG therapy between January 2000 and January 2007 at our institution. Prospectively recorded preoperative, intraoperative, and postoperative data were retrospectively screened for in-hospital mortality and major adverse cardiac events (MACE).

RESULTS

The delay between the onset of ST-elevation myocardial infarction symptoms and CABG procedures was within 6 hours in 37 patients, 7 to 24 hours in 21, 1 to 3 days in 15, 4 to 7 days in 24, and 8 to 14 days in 41 patients. Cardiogenic shock (Killip class > or = III) was present in 38 patients (28%), and 37 patients (27%) were referred for CABG after failed PCI. Overall in-hospital mortality was 8.7%, but mortality varied between 10.8% (< or = 6 hours), 23.8% (7 to 24 hours), 6.7% (1 to 3 days), 4.2% (4 to 7 days), and 2.4% (8 to 14 days), depending on time interval from symptom onset to operation. Overall, more nonsurvivors were women (58% versus 23%; p < 0.01), had higher preoperative cardiac troponin I levels (13.2 +/- 9.8 versus 4.5 +/- 4.2 ng/ml; p < 0.0001), and were more frequently in cardiogenic shock (83% versus 22%; p < 0.0001). Unadjusted univariable and risk-adjusted multivariable logistic regression analysis revealed age, female sex, preoperative cardiac troponin I levels, and cardiogenic shock to be the most potent predictors of in-hospital death and MACE.

CONCLUSIONS

CABG in ST-elevation myocardial infarction can be performed with acceptable risk by incorporating adequate management strategies. However, female sex, preoperative cardiac troponin I level, preoperative cardiogenic shock, and time to operation are major variables of mortality and morbidity results.

Coronary artery angioplasty for treatment of peri-operative myocardial ischaemia

Increasing numbers of elderly patients with severe co-existing medical diseases undergo major surgery. With these patients there is also an accompanying risk of age-related cardiovascular complications such as life-threatening myocardial ischaemia. We present a patient who suffered a myocardial infarction after a hemicolectomy and suffered a cardiac arrest in the recovery room. The therapeutic options available (e.g. coronary artery bypass grafting, acute percutaneous coronary angioplasty and peri-operative thrombolysis) are discussed and the successful management of the case by coronary angioplasty and stent implantation is described.

Antioxidant capacity of the human pericardial fluid: does gender have a role?

The aim of the present study was to assess the antioxidant capacity in the serum and pericardial fluid of patients undergoing heart surgery for coronary heart disease (CHD) or valvular heart disease (VHD) and to find out whether there are gender-related differences in the antioxidant defense. This study involved 85 patients (35 VHD and 50 CHD) undergoing elective heart surgery. Blood samples from the peripheral vein and from the pericardial fluid were taken intraoperatively. Variables determined in the serum and pericardial fluid were: total protein, albumin, uric acid and antioxidant capacity. In the total patient population the antioxidant capacity in the pericardial fluid was lower than in the serum but still relatively high as determined by two independent techniques. No major differences were seen in serum or pericardial fluid antioxidant capacity between the two patient groups. In the overall patient population uric acid (p<0.05), albumin (p<0.01) and total protein concentrations (p<0.01) were, however, significantly greater in the pericardial fluid of male than of female patients. The pericardial fluid may contribute to the local antioxidant defense of the myocardium. It appears that male gender confers advantage in this respect. It remains to be elucidated whether this finding has any implication for the higher risk for women of perioperative complications and of cardiovascular mortality after coronary bypass grafting or coronary angioplasty.

Cardiac surgery risk modeling for mortality: a review of current practice and suggestions for improvement

Risk models play a vital role in monitoring health care performances. Despite extensive research and widespread use of risk models in cardiac surgery, there are methodologic problems. We reviewed the methodology used for risk models for short-term mortality. The findings suggest that many risk models are developed in an ad hoc manner. Important aspects such as selection of risk factors, handling of missing values, and size of the data used for model development are not dealt with adequately. Methodologic details presented in publications are often sparse and unclear. Model development and validation processes are not always linked to the clinical aim of the model, which may affect their clinical validity. We make some suggestions in this review for improvement in methodology and reporting.

Frequency and prognosis of emergency coronary artery bypass grafting after percutaneous coronary intervention for acute myocardial infarction

We evaluated the frequency and prognosis of emergency coronary artery bypass grafting (CABG) after percutaneous coronary intervention (PCI) for acute myocardial infarction in a large, multicenter registry of contemporary PCI. In this study, emergency CABG occurred in 2% of cases, and was associated with high in-hospital mortality (20%) and with a high incidence of stroke (8%), renal failure requiring dialysis (8.3%), and bleeding (63.3%).

New surgical therapies for heart failure

A growing number of patients present with heart failure. Some of them may qualify for surgical correction of their cardiac condition. Since heart transplantation will always be available to only a small number of patients, several new surgical techniques have been developed for approval in heart failure patients. Classic interventions such as revascularization, valve repair, or valve replacement have been improved and modified to meet the need of heart failure patients. Several of these techniques are currently under investigation in large clinical trials. These trials will definitely have an impact on the development of surgical treatment of patients with heart failure.