Time to first new myocardial infarction in patients with severe angina and three-vessel disease comparing medical and early surgical therapy: A CASS registry study of survival

Elevated body mass index and use of coronary revascularization after cardiac catheterization

BACKGROUND

Obese persons suffer discrimination in society that may extend to health care use. We investigated whether overweight and obese patients are as likely to undergo coronary reperfusion or revascularization as patients of normal body weight.

METHODS

Detailed clinical data were collected for an inception cohort of patients from Alberta, Canada, who underwent cardiac catheterization between April 2001 and March 2004. The patients' likelihood of receiving any revascularization, percutaneous coronary intervention, or coronary artery bypass graft surgery in the year after cardiac catheterization was examined on the basis of body mass index (BMI) grouping. Use of revascularization was examined separately for patients with high- and low-risk coronary disease.

RESULTS

Of 27,460 patients who had BMI data recorded, 24% were of normal weight, 42% were overweight, and 35% were obese. Although overweight and obese patients were more likely to have percutaneous coronary intervention (adjusted hazard ratio [HR]=1.07, 95% confidence interval [CI], 1.01-1.12 and HR 1.08, 95% CI, 1.01-1.13, respectively), obese patients (BMI>30) were less likely to receive coronary artery bypass graft surgery (adjusted HR=0.93, 95% CI, 0.87-1.00). This was primarily because of less use of coronary artery bypass graft surgery for the most obese patients (obesity class III) with low-risk coronary anatomy (adjusted HR=0.61, 95% CI, 0.36-1.02).

CONCLUSION

The pattern of use of revascularization procedures after cardiac catheterization differs somewhat across BMI subgroups. These differences might be clinically appropriate, but they warrant further exploration.

Renal function, concomitant medication use and outcomes following acute coronary syndromes

BACKGROUND

Chronic kidney disease (CKD) is highly prevalent in patients with cardiovascular disease. We explored the associations of CKD with outcomes using combined data from two large acute coronary syndrome (ACS) trials. We also explored the associations of CKD with prescription patterns for common cardiovascular medications and the association of these prescription patterns with clinical outcomes.

METHODS

Patients were stratified by CKD stage using creatinine clearance (CrCl, ml/min) estimated by the modified MDRD equation using baseline core laboratory creatinine measures. Serum creatinine > or =1.5 mg/dl was an exclusion criterion for the SYMPHONY trials. Baseline characteristics and outcomes across CKD categories were compared and Cox proportional hazards regression was used to assess the relationship of renal insufficiency with clinical outcomes after adjusting for previously identified outcome predictors. Interactions between the use of specific medications and calculated CrCl were tested in the final Cox proportional hazards model predicting time to mortality.

RESULTS

Of 13 707 patients analysed, 6840 had CKD stage I (CrCl > or =90 ml/min), 5909 stage II (CrCl 60-89 ml/min), 955 stage III (CrCl 30-59 ml/min) and three stage IV (CrCl <30 ml/min). Patients with more advanced CKD (III) were older, more often female, non-smokers and more likely to have co-morbid diseases including diabetes mellitus, hypertension and congestive heart failure. Cardiovascular medications were used less frequently in patients with CKD. Unadjusted survival was poorer in patients with CKD stages > or =II. In adjusted analyses, for those with CrCl < or =91, each 10 ml/min increase in CrCl was associated with a significantly decreased risk of mortality (hazards ratio 0.897, 95% confidence interval 0.815-0.986) (P = 0.024). The interaction between use of angiotensin-converting enzyme (ACE) inhibitors and CrCl was significantly associated with outcomes; the benefit of drug therapy was greater among patients with CKD.

CONCLUSIONS

CKD is an independent predictor of risk among ACS patients, and is associated with less frequent use of proven medical therapies. More aggressive use of conventional cardiovascular therapies in patients with CKD and ACS may be warranted.

Chronic kidney disease, mortality, and treatment strategies among patients with clinically significant coronary artery disease

Cardiovascular disease is an important cause of mortality among patients with chronic kidney disease (CKD). This study describes associations between CKD, cardiac revascularization strategies, and mortality among patients with CKD and cardiovascular disease. All patients undergoing cardiac catheterization at Duke University Medical Center (1995 to 2000) with documented stenosis > or =75% of at least one coronary artery and available creatinine data were included. CKD was staged using creatinine clearance (CrCl) derived from the Cockcroft-Gault formula (normal, > or = 90 ml/min; mild, 60 to 89 ml/min; moderate, 30 to 59 ml/min; severe, 15 to 29 ml/min). Cox proportional-hazard regression estimated the relationship between clinical variables, including CrCl and percutaneous coronary artery intervention (PCI), coronary artery bypass grafting (CABG), medical management, and patient survival. There were 4584 patients included, and 24% had CrCl <60 ml/min. Each 10-ml/min decrement in CrCl was associated with an increase in mortality (hazard ratio, 1.14; P < 0.0001). CABG was associated with a survival benefit among patients with both normal renal function and patients with CKD compared with medical management. In patients with normal renal function, CABG was not associated with survival benefit over PCI. However, in patients with CKD, CABG was associated with improved survival. PCI was associated with a survival benefit compared with medical management among patients with normal, mildly, and moderately impaired renal function. Among patients with severe CKD, PCI was not associated with improved survival. CABG is associated with greater mortality reduction than PCI in severe CKD.

Guidelines for indications for coronary revascularization in The Netherlands

In 1996 the Minister of Public Health, Welfare and Sports in The Netherlands published a 'Planning Decree Special Interventions in the Heart'. She requested from the professional organizations guidelines for the indications for interventions in the heart. A working group was formed with representatives from the Dutch professional organizations for cardiology and thoracic surgery, to address this issue for patients with coronary artery disease. The working group confirmed the need to discuss all patients who are considered for either elective or emergency revascularization during a multidisciplinary consultation in (or with) one of the specialized Dutch hospitals. During this meeting of the 'heart team', at least one interventional cardiologist and one thoracic surgeon should be present. There are three possible outcomes of the heart team's consultations for each patient: drug therapy only ('conservative management'), coronary surgery or catheter intervention. For each case, the team should indicate the expected benefit, the risk of the intervention, the urgency and the estimated waiting time. The guidelines presented in this paper address these issues for three patient categories: stable angina pectoris, unstable angina pectoris and acute myocardial infarction.

Coronary artery surgery: the end of the beginning

In each of the first three decades of myocardial revascularization, conventional treatment has been revised completely. This lecture comments on three areas of discovery that have shaped the evolution of myocardial revascularization: science, technology development, and revascularization. The discoveries in all three areas are inexorably interrelated. The single greatest lesson learned so far is that conduit performance carries more prognostic weight than any other factor. We have observed that vein graft atherosclerosis is predictable, and that the first-generation lipid lowering drugs have a favorable effect in patients who achieve marked LDL reduction. Biologically better revascularization begins with use of the internal thoracic artery for grafting to the anterior descending coronary artery. As the results of internal thoracic artery grafting are widely reported, arterial bypass revascularization has expanded, notably by radial and gastroepiploic arteries. The results of bilateral internal thoracic artery grafting are discussed, including large-scale registry results of internal thoracic artery usage in the United States. The internal thoracic artery is significantly underutilized. Diabetes affects both endoluminal and surgical revascularization. The new pharmacology in cardiology interventions shows promise in diminishing restenosis and thrombosis even in diabetic patients. Conversely, extended internal thoracic artery grafting may also benefit diabetic patients. Now we are entering a new age of minimally invasive coronary surgery. We have passed through the early stages of mini-thoracotomy, and we are moving on to access through 1-cm ports, intrathoracic cannulation, antegrade and retrograde myocardial protection, and computer guided three-dimensional vision and instrumentation. The potential for robotic control adds greater precision, ease of use, and safety. This new technology will be integrated with diagnostic information, intraoperative monitoring, anesthesia and perfusion data, cost accounting, and surgical note transcription. The operating room of the future will package intraoperative information and is adaptable to all surgical specialties. The future of coronary artery surgery will depend on minimally invasive techniques, all-arterial grafting, and selective lipid modification to reduce progressive atherosclerosis. The conclusion of this decade marks the end of the beginning. The new generation of cardiothoracic surgeons will share in an array of technology and research unmatched in previous decades.

Effects of captopril on ischemic events after myocardial infarction. Results of the Survival and Ventricular Enlargement trial. SAVE Investigators

BACKGROUND

In the Survival and Ventricular Enlargement (SAVE) trial, recurrent myocardial infarction (MI) was the most important predictor of a poor outcome and conferred a sevenfold increase in risk of death. The purpose of this study was to determine the predictors of recurrent MI in study participants and to examine the influence of the angiotensin-converting enzyme inhibitor captopril on this and other myocardial ischemic events.

METHODS AND RESULTS

The 2231 patients had survived the acute phase of MI (3 to 16 days) and had a radionuclide ventricular ejection fraction < or = 40%. Patients were randomly assigned to receive double-blind treatment with either placebo or captopril and were followed for an average of 42 months. The influence of captopril on recurrent MI, cardiac revascularization procedures, and hospitalization with unstable angina was examined. The likelihood of recurrent MI was greater in patients with an MI or functional disability before the index infarction and higher systolic pressure (all P < .001) but was not influenced by baseline left ventricular ejection fraction. Therapy with captopril reduced the risk of development of recurrent MI by 25% (95% confidence intervals, 5% to 40%; P = .015) and the risk of death after recurrent MI by 32% (95% confidence intervals, 4% to 51%; P = .029). Captopril-assigned patients were also less likely to require cardiac revascularization procedures (P = .010), but hospitalization for unstable angina was unaltered. When all three of these major coronary ischemic events were considered together, captopril therapy reduced the risk (14% risk reduction; 95% confidence intervals, 0% to 26%; P = .047).

CONCLUSIONS

In post-MI patients with asymptomatic left ventricular dysfunction, long-term administration of captopril reduced recurrence of MI and the need for cardiac revascularization but had no influence on the rate of hospitalization with a discharge diagnosis of unstable angina. The finding that the recurrence of MI was independent of left ventricular ejection fraction suggests that captopril could be useful in preventing recurrent MI in patients with more preserved left ventricular function. The need for cardiac revascularization was reduced in patients receiving long-term captopril therapy, suggesting either an anti-ischemic effect or the ability of the angiotensin-converting enzyme inhibitor to modify the atherosclerotic process in survivors of MI.

Early and late survival after coronary-artery surgery

Between 1970 and 1985, 1801 patients underwent coronary-artery surgery without associated valvular surgery. Eighty-four per cent of patients were male and the mean (+/- SD) age was 55.7 +/- 8.3 years. Of the patients, 18.7% were from the Coronary Care Unit and 6.5% had diabetes. The hospital mortality rate for the whole group was 3.5%. Patients from the Coronary Care Unit had the highest (8.9%) hospital mortality rate compared with those patients who were not from the Coronary Care Unit (2.1%; P less than 0.001). Other factors which increased the hospital mortality rate significantly were the number of diseased vessels (P less than 0.01), the degree of left main coronary-artery stenosis (P less than 0.001), an earlier year of surgery (P less than 0.01) and female sex (P less than 0.01). After these were taken into account, no other factors (for example, age, preoperative infarction, presence of left-ventricular aneurysm, left-ventricular end-diastolic pressure, diabetes, use of mammary-arterial grafts or the need for endarterectomy) affected the mortality rate. Patients were followed-up for a mean (+/- SD) of 4.4 +/- 2.8 years. The five-year survival rate for all patients was 88% and the 10-year survival rate was 65%. Cox regression analysis showed that the significant indicators of decreased long-term survival were undergoing operation directly from the Coronary Care Unit (P less than 0.001), left main coronary-artery stenosis (P less than 0.01), the number of grafted vessels (P less than 0.01), concomitant surgery for aneurysm (P less than 0.001), year of surgery (P less than 0.01). Seventy-nine per cent of patients were free of angina pectoris at five years after operation. The year of surgery (P less than 0.001) and preoperative myocardial infarction (P less than 0.05) were the best predictors of recurrent angina. In the long term, recurrent angina remains a problem, although this may change with the increased use of mammary-arterial grafts.