Interactive effects of age and other risk factors on long-term survival after coronary artery surgery

In-hospital mortality of patients with severe left ventricular dysfunction undergoing coronary artery bypass grafting in Iranian population

Background

Historically, coronary artery bypass grafting is associated with a higher mortality rate in patients with severe heart failure. This study aimed to assess the in-hospital mortality of CABG in patients with severe heart failure in Iranian patients and to identify factors associated with adverse outcomes.

Methods

This retrospective descriptive study enrolled patients with severe heart failure who underwent coronary artery bypass surgery from 2015 to 2020 in Madani Hospital, affiliated with Tabriz University of Medical Sciences.

Results

A total of 865 consecutive patients with a mean age of 60.65 ± 10.00 were enrolled in the study. Of all participants, 175 were female (20.4%), and 684 were male. The overall mortality rate was 9.5%. In the univariate analysis, predictors of ICU mortality were age, female sex, DM, and renal failure (P value < 0.05). None of the factors studied was an independent predictor of ICU mortality in the multivariate analysis.

Conclusion

This study established that although coronary artery bypass surgery is reported to have low mortality and postoperative morbidity in patients with severe heart failure, there are still centers that face higher mortality rates in these patients. Improving these patients' outcomes would be possible through identifying the associated risk factors and pre-and postoperative management.

Reduced Long-Term Relative Survival in Females and Younger Adults Undergoing Cardiac Surgery: A Prospective Cohort Study

OBJECTIVES

To assess long-term survival and mortality in adult cardiac surgery patients.

METHODS

8,564 consecutive patients undergoing cardiac surgery in Trondheim, Norway from 2000 until censoring 31.12.2014 were prospectively followed. Observed long-term mortality following surgery was compared to the expected mortality in the Norwegian population, matched on gender, age and calendar year. This enabled assessment of relative survival (observed/expected survival rates) and relative mortality (observed/expected deaths). Long-term mortality was compared across gender, age and surgical procedure. Predictors of reduced survival were assessed with multivariate analyses of observed and relative mortality.

RESULTS

During follow-up (median 6.4 years), 2,044 patients (23.9%) died. The observed 30-day, 1-, 3- and 5-year mortality rates were 2.2%, 4.4%, 8.2% and 13.8%, respectively, and remained constant throughout the study period. Comparing observed mortality to that expected in a matched sample from the general population, patients undergoing cardiac surgery showed excellent survival throughout the first seven years of follow-up (relative survival ≥ 1). Subsequently, survival decreased, which was more pronounced in females and patients undergoing other procedures than isolated coronary artery bypass grafting (CABG). Relative mortality was higher in younger age groups, females and patients undergoing aortic valve replacement (AVR). The female survival advantage in the general population was obliterated (relative mortality ratio (RMR) 1.35 (1.19-1.54), p<0.001). Increasing observed long-term mortality seen with ageing was due to population risk, and younger age was independently associated with increased relative mortality (RMR per 5 years 0.81 (0.79-0.84), p<0.001)).

CONCLUSIONS

Cardiac surgery patients showed comparable survival to that expected in the general Norwegian population, underlining the benefits of cardiac surgery in appropriately selected patients. The beneficial effect lasted shorter in younger patients, females and patients undergoing AVR or other procedures than isolated CABG. Thus, the study identified three groups that need increased attention for further improvement of outcomes.

Changing health behaviors to improve health outcomes after angioplasty: a randomized trial of net present value versus future value risk communication

Patients who have undergone angioplasty experience difficulty modifying at-risk behaviors for subsequent cardiac events. The purpose of this study was to test whether an innovative approach to framing of risk, based on 'net present value' economic theory, would be more effective in behavioral intervention than the standard 'future value approach' in reducing cardiovascular morbidity and mortality following angioplasty. At baseline, all patients completed a health assessment, received an individualized risk profile and selected risk factors for modification. The intervention randomized patients into two varying methods for illustrating positive effects of behavior change. For the experimental group, each selected risk factor was assigned a numeric biologic age (the net present value) that approximated the relative potential to improve current health status and quality of life when modifying that risk factor. In the control group, risk reduction was framed as the value of preventing future health problems. Ninety-four percent of patients completed 2-year follow-up. There was no difference between the rates of death, stroke, myocardial infarction, Class II-IV angina or severe ischemia (on non-invasive testing) between the net present value group and the future value group. Our results show that a net present risk communication intervention did not result in significant differences in health outcomes.

[Meanings and attitudes of patients who undergo cardiac surgery: influence of sociodemographic variables]

The aim of this study was to verify the influence-of sociodemographic variables on patients' meanings and attitudes related to cardiac surgery. A hundred twenty five patients in preoperative period were interviewed. Data were collected throughout Meanings of Patients related to Cardiac Surgery and Beliefs (MPRCS), Beliefs, Values and Feelings related to Cardiac Surgery (BVFCS) instruments and they were analyzed by using Pearson's correlation coefficient and Mann-Whitney and Kruskal-Wallis tests. It was observed statistical significant correlations between age, number of children, income and the positive factors of MPRCS instrument. Gender, level of education, previous stressing events, living arrangements, and race were the sociodemographic variables that were associated to the patients' meanings and attitudes. It was concluded that meanings and attitudes of these patients were influenced by some sociodemographic variables, and these results can be relevant for planning and implementing some educative practices.

Percutaneous Intervention Versus Coronary Bypass Surgery for Patients Older Than 70 Years of Age With High-Risk Unstable Angina

BACKGROUND

The Angina With Extremely Serious Operative Mortality Evaluation (AWESOME) study was a multicenter Veterans Affairs randomized trial and registry that compared long-term survival of percutaneous coronary intervention with coronary artery bypass graft surgery for the treatment of patients with medically refractory myocardial ischemia and at least one additional risk factor for an adverse outcome with bypass. Both the randomized trial and the registry demonstrated comparable 3-year survival. The purpose of this study was to compare bypass and percutaneous intervention survival of AWESOME patients who were older than 70 years of age.

METHODS

Over a 5-year period (1995 to 2000), 2,431 patients with medically refractory myocardial ischemia and at least one of the following five risk factors (prior heart surgery, myocardial infarction within 7 days, left ventricular ejection fraction less than 35%, age > 70 years, intraaortic balloon pump requirement to stabilize) were identified. Of these patients, 1,278 were older than 70 years of age. Eight hundred, seventy-one patients were turned down by at least one physician, 407 were acceptable to both physician and surgeon for randomization, and 236 (60%) consented to randomization. Of the 1,042 eligible patients who were not randomized, 871 had their revascularization directed by a physician who was not involved in the study. One hundred, seventy-one patients who were acceptable for randomization by both the interventional cardiologist and the cardiac surgeon refused consent.

RESULTS

Bypass and percutaneous intervention survival were compared using Kaplan-Meier curves and log rank tests. Bypass and percutaneous intervention 36-month survival rates for patients older than 70 years of age were 76% and 75%, respectively, among the eligible patients. Survival was 71% and 78% among those patients who were randomized and 76% and 67% in the physician-directed subgroup. Of those patients who chose their revascularization techniques, the survivals were 79% and 85%, respectively. The survival differences are not large, and none of the global log rank tests of bypass compared with percutaneous intervention survival showed a statistically significant difference over 5 years.

CONCLUSIONS

Both the randomized and registry subgroups of patients who were older than 70 years of age support the trial conclusions that either bypass or percutaneous intervention effectively relieves medically refractory ischemia among high-risk unstable angina patients whose age was greater than 70 years.

Smoking cessation reduces mortality after coronary artery bypass surgery: a 20-year follow-up study

OBJECTIVES

The goal of this study was to determine the influence of smoking cessation on mortality after coronary artery bypass graft surgery (CABG), which has still not been established clearly.

BACKGROUND

Cigarette smoking is one of the known major risk factors of coronary artery disease.

METHODS

One thousand and forty-one patients underwent CABG between 1971 and 1980. The preoperative and postoperative smoking habits of 985 patients (95%) could be retrieved and were analyzed in a multivariate Cox analysis.

RESULTS

The median follow-up was 20 years (range 13 to 26 years). Smoking status before surgery did not entail an increased risk of mortality: patients who had smoked before surgery and those who had not smoked in the year before surgery had a similar probability of survival. However, smoking cessation after surgery was an important independent predictor of a lower risk of death and coronary reintervention during the 20-year follow-up when compared with patients who continued smoking. In analyses adjusted for baseline characteristics, the persistent smokers had a greater relative risk (RR) of death from all causes (RR 1.68 [95% confidence interval 1.33 to 2.13]) and cardiac death (RR 1.75 [1.30 to 2.37]) as compared with patients who stopped smoking for at least one year after surgery. The estimated benefit of survival for the quitters increased from 3% at five years to 14% at 15 years. The quitters were less likely to undergo repeat CABG or a percutaneous coronary angioplasty procedure (RR 1.41 [1.02 to 1.94]).

CONCLUSIONS

Patients who continued to smoke after CABG had a greater risk of death than patients who stopped smoking. They also underwent repeat revascularization procedures more frequently. Cessation of smoking is therefore strongly recommended after CABG. Clinicians are encouraged to start or to continue smoking-cessation programs in order to help smokers to quit smoking, especially after CABG.

Effects of nicotine gum on coronary vasomotor responses during sympathetic stimulation in patients with coronary artery stenosis

Smoking-cessation rates may be improved by nicotine-replacement therapy that reduces withdrawal symptoms. However, nicotine may have adverse effects on coronary circulation. The purpose of this study was to examine the short-term effects of nicotine gum chewing on the dimensions of coronary arteries of patients with coronary artery disease and on the response of coronary vessels to sympathetic stimulation caused by the cold pressor test. In 17 patients who were past chronic cigarette smokers, cross-sectional areas of 32 coronary artery stenoses and 32 adjacent apparently normal segments were measured by using quantitative coronary angiography at baseline and after a cold pressor test before and after nicotine gum chewing. The cold pressor test produces an increase in arterial pressure without any change in heart rate. These changes were similar before and after nicotine gum. Before nicotine gum, the cross-sectional area of coronary stenoses and apparently normal segments was significantly and similarly reduced during the cold pressor test (-11+/-12% and -11+/-12%, respectively; both p values <0.0001 vs. baseline). After nicotine gum, baseline cross-sectional area was not modified, and response to the cold pressor test was similar to that observed before nicotine gum (-11+/-18% and -12+/-12%, respectively; both p values <0.0001 vs. baseline). In conclusion, nicotine-replacement therapy by using nicotine gum does not reduce the surface area of normal and diseased coronary segments and does not enhance the constricting effect of sympathetic stimulation produced by the cold pressor test. Thus nicotine gum may be considered a relatively safe drug in patients who need nicotine-replacement therapy to stop smoking.

Reducing the risk after coronary artery bypass surgery: documentation of risk factors and communication between hospital and general practice

A retrospective descriptive study of patients who had had coronary artery bypass surgery was carried out to assess the completeness of recording of risk factors in case notes in hospital and in general practice, and to determine the prevalence of documented risk factors in patients who have had coronary artery bypass surgery. Data from reviews of hospital case notes and questionnaires to general practitioners were used to describe the frequency of documenting coronary risk factors and preventative advice in case notes and in correspondence between general practitioners and hospital doctors. Documentation of risk in hospital records revealed that all 102 patients had been assessed for family history, hypertension and current smoking, but 9 (9%) had no record of serum cholesterol, 35 (34%) patients did not have a record of their blood glucose, and in 83 (81%) patients there was no evidence that obesity had been assessed. Documentation of risk factors in general practice records identified that out of 77 patients, all had their blood pressure and smoking status recorded but 29 (38%) had not been assessed for hypercholesterolaemia. From the hospital records, the prevalence of risk factors in the sample population was 41% for hypertension or raised blood pressure, 49% for hypercholesterolaemia, 12% for current smoking and 8% for diabetes mellitus. In conclusion, patients who have had coronary artery bypass surgery have substantial needs for secondary prevention. A more structured approach to risk factor assessment and preventative care should begin as soon as the diagnosis of coronary heart disease is made, and should not be postponed until the patient has deteriorated to the point of needing bypass surgery.

Smoking and cardiac events after venous coronary bypass surgery. A 15-year follow-up study

BACKGROUND

The long-term clinical effects of smoking and smoking cessation after venous coronary bypass surgery have not been well established.

METHODS AND RESULTS

Four hundred fifteen patients who underwent venous coronary bypass surgery between April 1976 and April 1977 were followed up prospectively for 15 years. Multivariate Cox survival analysis revealed that patients who smoked at the time of surgery had no elevated risks for clinical events compared with nonsmokers. However, smoking behavior at 1 and 5 years after surgery appeared to be an important predictor of clinical events during the subsequent follow-up period. Compared with patients who stopped smoking since surgery, smokers at 1 year after surgery had more than twice the risk for myocardial infarction and reoperation. Patients who were still smoking at 5 years after surgery had even more elevated risks for myocardial infarction and reoperation and a significantly increased risk for angina pectoris compared with patients who stopped smoking since surgery and patients who never smoked. Patients who started to smoke again within 5 years after surgery had increased risks for reoperation and angina pectoris. No differences in outcome were found between patients who stopped smoking since surgery and nonsmokers.

CONCLUSIONS

Our results show that smoking cessation after coronary bypass surgery may have important beneficial effects on clinical events during long-term follow-up.

The effect of noncritical coronary artery disease on long-term survival

This study was designed to determine the impact of noncritical (less than 70% narrowing of the luminal diameter) coronary stenoses on the long-term survival rate of patients with coronary artery disease. The survival rate of 3,342 patients with normal coronary arteries (Group 1A) was compared with that of 2,184 patients with only noncritical stenoses (Group 1B). Similarly, the survival rate of 1,128 patients with one or more critical lesions (Group 2A) was compared with that of 5,944 cases with noncritical plus critical lesions (Group 2B). Patients with noncritical lesions had significantly lower 10-year survival rates (85.8%) than did those with normal coronary arteries (90.1%). However, the difference in survival rate was attributable to older age, male sex, and higher prevalence of cigarette smoking, diabetes mellitus, and hypertension in Group 1B than in Group 1A; presence of noncritical stenoses was not a statistically significant independent determinant of survival. Long-term survival rates of the patients with one or more critical lesions (Group 2A) were equivalent to that of patients with critical stenoses plus one or more noncritical lesions (Group 2B). Therefore, 1) patients with only noncritical stenoses have more risk factors for coronary artery disease than do those with normal coronary arteries; 2) these patients have a reduced long-term survival rate that reflects these risk factors rather than the presence of noncritical lesions; and 3) in patients with critical lesions, the presence of additional non-critical stenoses does not affect the long-term survival rate.

Expanding access to coronary artery bypass surgery: who stands to gain?

OBJECTIVE

To determine the perceptions of general practitioners (GPs) about the benefits of coronary artery bypass surgery, in terms of gains in life expectancy, for different groups of patients.

DESIGN

A questionnaire survey of all GPs in Northern Ireland.

SETTING

A survey conducted collaboratively by the departments of public health medicine in each of the four health boards in the province, serving a total population of 1.5 million.

MAIN OUTCOME MEASURES

The median and mean gain in life expectancy perceived by groups of doctors for smoking and non-smoking male and female 55 year old patients. The percentage of 50 year old and 70 year old non-smoking patients considered likely to have their lives extended with bypass surgery. Differences were assessed using the Mann-Whitney U test for unpaired samples and the Wilcoxon signed rank tests for paired.

RESULTS

541 GPs replied (response rate 56%). The median (and mean) perceived gain in life expectancy after cardiac surgery for non-smoking 55 year old subjects was 120 (104) months for men and 120 (112) months for women (z = 6.42; P < 0.0001; Wilcoxon signed rank test). For male and female smokers of the same age, the perceived gains were 48 (47) and 60 (52) months respectively (z = 6.72; P < 0.0001; Wilcoxon signed ranks test), both figures being significantly different than for non-smokers. The median (and mean) percentage of patients that the doctors considered would have their lives extended by bypass surgery was 70 (64) of every 100 "young" patients and 40 (42) of every 100 "old" patients, (z = 16.2; P < 0.0001).

CONCLUSIONS

These results point to a significant overestimation of the benefits of coronary artery bypass surgery by GPs in Northern Ireland and to a need to develop guidelines for referral.

Long-term survival of patients with coronary artery disease during the 1970s. A cohort study

STUDY OBJECTIVE

This study was undertaken to determine the effects of altered risk factors and treatment modalities on the short- and long-term survival of patients with documented coronary artery disease whose conditions were diagnosed from 1972 through 1982.

STUDY DESIGN

The study was a retrospective database analysis of clinical, angiographic, and follow-up information.

SETTING

Data from all patients referred for cardiac catheterization at the Baptist Memorial Hospital, Memphis, Tenn, were studied.

PATIENTS

Risk factors and survival of patients who underwent cardiac catheterization from 1972 through 1982 and who were followed up for at least 5 years were evaluated. Cohort A included 1,821 patients studied from 1972 through 1977; cohort B included 5,369 patients studied between 1977 and the end of 1982. Each cohort was subdivided based on type of therapy (medical or surgical) that the patients received.

MEASUREMENTS AND RESULTS

The 30-day (short-term) and 5-year (long-term) survival rates were compared by life table methods. Short-term survival improved significantly in both medical (from 94.9% to 97.5%, p < 0.001) and surgical (from 95.5% to 97.6%, p < 0.001) groups from cohort A to cohort B. Long-term survival, however, did not differ significantly between the two cohorts. In the medical group, 5-year survival in cohort A was 86.3% and in cohort B it was 86.9% (p = NS); in the surgical group, cohort A it was 89.1% while in cohort B it was 89.4% (p = NS). Prevalence of both cigarette smoking and hypercholesterolemia declined significantly from cohort A to cohort B in both surgical and medical groups. However, advanced age, female gender, and previous myocardial infarction were significantly more common in cohort B than in cohort A for both treatment groups.

CONCLUSIONS

These results indicate that during the study period, a significant decline in short-term mortality occurred for patients with angiographically documented coronary artery disease. Long-term survival did not, however, improve possibly due to a complex interplay between factors that promote coronary artery disease, eg, cigarette abuse and hypercholesterolemia, and factors that determine survival, eg, increase in age and history of prior infarction and advances in medical and surgical therapy.