Alastair C.H. Pell

Smoke-free Legislation and Hospitalizations for Acute Coronary Syndrome

BACKGROUND Previous studies have suggested a reduction in the total number of hospital admissions for acute coronary syndrome after the enactment of legislation banning smoking in public places. However, it is unknown whether the reduction in admissions involved nonsmokers, smokers, or both. METHODS Since the end of March 2006, smoking has been prohibited by law in all enclosed public places throughout Scotland. We collected information prospectively on smoking status and exposure to secondhand smoke based on questionnaires and biochemical findings from all patients admitted with acute coronary syndrome to nine Scottish hospitals during the 10-month period preceding the passage of the legislation and during the same period the next year. These hospitals accounted for 64% of admissions for acute coronary syndrome in Scotland, which has a population of 5.1 million. RESULTS Overall, the number of admissions for acute coronary syndrome decreased from 3235 to 2684--a 17% reduction (95% confidence interval, 16 to 18)--as compared with a 4% reduction in England (which has no such legislation) during the same period and a mean annual decrease of 3% (maximum decrease, 9%) in Scotland during the decade preceding the study. The reduction in the number of admissions was not due to an increase in the number of deaths of patients with acute coronary syndrome who were not admitted to the hospital; this latter number decreased by 6%. There was a 14% reduction in the number of admissions for acute coronary syndrome among smokers, a 19% reduction among former smokers, and a 21% reduction among persons who had never smoked. Persons who had never smoked reported a decrease in the weekly duration of exposure to secondhand smoke (P<0.001 by the chi-square test for trend) that was confirmed by a decrease in their geometric mean concentration of serum cotinine from 0.68 to 0.56 ng per milliliter (P<0.001 by the t-test). CONCLUSIONS The number of admissions for acute coronary syndrome decreased after the implementation of smoke-free legislation. A total of 67% of the decrease involved nonsmokers. However, fewer admissions among smokers also contributed to the overall reduction.

Obesity paradox in a cohort of 4880 consecutive patients undergoing percutaneous coronary intervention.

AIMS We sought to investigate the impact of body mass index (BMI) on long-term all-cause mortality in patients following first-time elective percutaneous coronary intervention (PCI). METHODS AND RESULTS We used the Scottish Coronary Revascularisation Register to undertake a cohort study of all patients undergoing elective PCI in Scotland between April 1997 and March 2006 inclusive. We excluded patients who had previously undergone revascularization. There were 219 deaths within 5 years of 4880 procedures. Compared with normal weight individuals, those with a BMI > or =27.5 and <30 were at reduced risk of dying (HR 0.59, 95% CI 0.39-0.90, 95%, P = 0.014). There was no attenuation of the association after adjustment for potential confounders, including age, hypertension, diabetes, and left ventricular function (adjusted HR 0.59, 95% CI 0.39-0.90, P = 0.015), and there were no statistically significant interactions. The results were unaltered by restricting the analysis to events beyond 30 days of follow-up. CONCLUSION Among patients undergoing percutaneous intervention for coronary artery disease, increased BMI was associated with improved 5 year survival. Among those with established coronary disease, the adverse effects of excess adipose tissue may be offset by beneficial vasoactive properties.

Effect of socioeconomic deprivation on waiting time for cardiac surgery: retrospective cohort study

Abstract Objective: To determine whether the priority given to patients referred for cardiac surgery is associated with socioeconomic status. Design: Retrospective study with multivariate logistic regression analysis of the association between deprivation and classification of urgency with allowance for age, sex, and type of operation. Multivariate linear regression analysis was used to determine association between deprivation and waiting time within each category of urgency, with allowance for age, sex, and type of operation. Setting: NHS waiting lists in Scotland. Participants: 26 642 patients waiting for cardiac surgery, 1 January 1986 to 31 December 1997. Main outcome measures: Deprivation as measured by Carstairs deprivation category. Time spent on NHS waiting list. Results: Patients who were most deprived tended to be younger and were more likely to be female. Patients in deprivation categories 6 and 7 (most deprived) waited about three weeks longer for surgery than those in category 1 (mean difference 24 days, 95% confidence interval 15 to 32). Deprived patients had an odds ratio of 0.5 (0.46 to 0.61) for having their operations classified as urgent compared with the least deprived, after allowance for age, sex, and type of operation. When urgent and routine cases were considered separately, there was no significant difference in waiting times between the most and least deprived categories. Conclusions: Socioeconomically deprived patients are thought to be more likely to develop coronary heart disease but are less likely to be investigated and offered surgery once it has developed. Such patients may be further disadvantaged by having to wait longer for surgery because of being given lower priority.

Impact of changing diagnostic criteria on incidence, management, and outcome of acute myocardial infarction: retrospective cohort study

Acute myocardial infarction used to be defined by criteria based on symptoms, changes in electrocardiograms and the concentrations of cardiac enzymes, as recommended by the World Health Organization.1 Specific markers of myocardial damage, including troponin T, are more sensitive indicators than total creatine kinase concentration for ischaemic myocardial necrosis and prognosis.2 In 2000, the European Society of Cardiology and the American College of Cardiology recommended changing the diagnostic criteria for acute myocardial infarction to include raised troponin T concentrations in addition to changes in electrocardiograms or coronary intervention.3 Some patients with acute coronary syndrome who had been diagnosed as having unstable angina are now classified as having myocardial infarction. We investigated the impact of using the new criteria on the incidence, management, and outcome of myocardial infarction. Since 1997, all patients admitted with chest pain to Monklands Hospital, Airdrie, had their troponin T concentrations measured. We identified patients …

Effect of "fast track" admission for acute myocardial infarction on delay to thrombolysis.

OBJECTIVE--To evaluate the impact of a fast track triage system for patients with acute myocardial infarction. DESIGN--Comparison of delays in admission to hospital and in receiving thrombolytic treatment before and after introducing fast track system with delays recorded in 1987-8. Patients fulfilling clinical and electrocardiographic criteria for myocardial infarction were selected for rapid access to the cardiac care team, bypassing evaluation by the medical registrar. SETTING--Major accident and emergency, cardiac and trauma centre. SUBJECTS--359 patients admitted to the cardiac care unit during 1 February to 31 July 1990 with suspected acute infarction. MAIN OUTCOME MEASURES--Accuracy of diagnosis and delay from arrival at hospital to thrombolytic treatment. RESULTS--248 of the 359 patients had myocardial infarction confirmed, of whom 127 received thrombolytic treatment. The fast track system correctly identified 79 out of 127 (62%) patients who subsequently required thrombolytic treatment. 95% (79/83) of patients treated with thrombolysis after fast track admission had the diagnosis confirmed by electrocardiography and enzyme analysis. The median delay from hospital admission to thrombolytic treatment fell from 93 minutes in 1987-8 to 49 minutes in fast track patients (p less than 0.001). Delay in admission to the cardiac care unit was reduced by 47% for fast tract patients (median 60 minutes in 1987-8 v 32 minutes in 1990, p less than 0.001) and by 25% for all patients (60 minutes v 45 minutes, p less than 0.001). CONCLUSION--This fast track system requires no additional staff or equipment, and it halves inhospital delay to thrombolytic treatment without affecting the accuracy of diagnosis among patients requiring thrombolysis.

Percutaneous Coronary Intervention in the Elderly Changes in Case-Mix and Periprocedural Outcomes in 31 758 Patients Treated Between 2000 and 2007

Background— The elderly account for an increasing proportion of the population and have a high prevalence of coronary heart disease. Percutaneous coronary intervention (PCI) is the most common method of revascularization in the elderly. We examined whether the risk of periprocedural complications after PCI was higher among elderly (age ≥75 years) patients and whether it has changed over time. Methods and Results— The Scottish Coronary Revascularization Register was used to undertake a retrospective cohort study on all 31 758 patients undergoing nonemergency PCI in Scotland between April 2000 and March 2007, inclusive. There was an increase in the number and percentage of PCIs undertaken in elderly patients, from 196 (8.7%) in 2000 to 752 (13.9%) in 2007. Compared with younger patients, the elderly were more likely to have multivessel disease, multiple comorbidity, and a history of myocardial infarction or coronary artery bypass grafting (χ2 tests, all P <0.001). The elderly had a higher risk of major adverse cardiovascular events within 30 days of PCI (4.5% versus 2.7%, χ2 test P <0.001). Over the 7 years, there was a significant increase in the proportion of elderly patients who had multiple comorbidity (χ2 test for trend, P <0.001). Despite this, the underlying risk of complications did not change significantly over time either among the elderly (χ2 test for trend, P =0.142) or overall (χ2 test for trend, P =0.083). Conclusions— Elderly patients have a higher risk of periprocedural complications and account for an increasing proportion of PCIs. Despite this, the risk of complications after PCI has not increased over time.Background—The elderly account for an increasing proportion of the population and have a high prevalence of coronary heart disease. Percutaneous coronary intervention (PCI) is the most common method of revascularization in the elderly. We examined whether the risk of periprocedural complications after PCI was higher among elderly (age ≥75 years) patients and whether it has changed over time. Methods and Results—The Scottish Coronary Revascularization Register was used to undertake a retrospective cohort study on all 31 758 patients undergoing nonemergency PCI in Scotland between April 2000 and March 2007, inclusive. There was an increase in the number and percentage of PCIs undertaken in elderly patients, from 196 (8.7%) in 2000 to 752 (13.9%) in 2007. Compared with younger patients, the elderly were more likely to have multivessel disease, multiple comorbidity, and a history of myocardial infarction or coronary artery bypass grafting (&khgr;2 tests, all P<0.001). The elderly had a higher risk of major adverse cardiovascular events within 30 days of PCI (4.5% versus 2.7%, &khgr;2 test P<0.001). Over the 7 years, there was a significant increase in the proportion of elderly patients who had multiple comorbidity (&khgr;2 test for trend, P<0.001). Despite this, the underlying risk of complications did not change significantly over time either among the elderly (&khgr;2 test for trend, P=0.142) or overall (&khgr;2 test for trend, P=0.083). Conclusions—Elderly patients have a higher risk of periprocedural complications and account for an increasing proportion of PCIs. Despite this, the risk of complications after PCI has not increased over time.

Validity of Self-Reported Smoking Status: Comparison of Patients Admitted to Hospital with Acute Coronary Syndrome and the General Population

Many studies rely on self-reported smoking status. We hypothesized that patients with acute coronary syndrome (ACS), a smoking-related condition, would be more prone to misclassify themselves as ex-smokers, because of pressure to quit. We compared patients admitted with ACS with a general population survey conducted in the same country at a similar time. We determined whether ACS patients who classified themselves as ex-smokers (n = 635) were more likely to have cotinine levels suggestive of smoking deception than self-reported ex-smokers in the general population (n = 289). On univariate analysis, the percentage of smoking deceivers was similar among ACS patients and the general population (11% vs. 12%, p = .530). Following adjustment for age, sex and exposure to environmental tobacco smoke, ACS patients were significantly more likely to misclassify themselves (adjusted OR = 14.06, 95% CI 2.13-93.01, p = .006). There was an interaction with age whereby the probability of misclassification fell significantly with increasing age in the ACS group (adjusted OR = 0.95, 95% CI 0.93-0.97, p<.001), but not in the general population. Overall, smoking deception was more common among ACS patients than the general population. Studies comparing patients with cardiovascular disease and healthy individuals risk introducing bias if they rely solely on self-reported smoking status. Biochemical confirmation should be undertaken in such studies.

Comparison of mass and targeted screening strategies for cardiovascular risk: simulation of the effectiveness, cost-effectiveness and coverage using a cross-sectional survey of 3921 people

Background Cardiovascular primary prevention should be targeted at those with the highest global risk. However, it is unclear how best to identify such individuals from the general population. The aim of this study was to compare mass and targeted screening strategies in terms of effectiveness, cost effectiveness and coverage. Methods The Scottish Health Survey provided cross-sectional data on 3921 asymptomatic members of the general population aged 40–74 years. We undertook simulation models of five screening strategies: mass screening, targeted screening of deprived communities, targeted screening of family members and combinations of the latter two. Results To identify one individual at high risk of premature cardiovascular disease using mass screening required 16.0 people to be screened at a cost of £370. Screening deprived communities targeted 17% of the general population but identified 45% of those at high risk, and identified one high-risk individual for every 6.1 people screened at a cost of £141. Screening family members targeted 28% of the general population but identified 61% of those at high risk, and identified one high-risk individual for every 7.4 people screened at a cost of £170. Combining both approaches enabled 84% of high risk individuals to be identified by screening only 41% of the population. Extending targeted to mass screening identified only one additional high-risk person for every 58.8 screened at a cost of £1358. Conclusions Targeted screening strategies are less costly than mass screening, and can identify up to 84% of high-risk individuals. The additional resources required for mass screening may not be justified.

Families of patients with premature coronary heart disease: an obvious but neglected target for primary prevention.

Risk of premature coronary heart disease is increased in the families of affected patients. C K Chow and colleagues argue that targeting relatives for primary prevention would be an effective policy

Comparison of survival following coronary artery bypass grafting vs. percutaneous coronary intervention in diabetic and non-diabetic patients: retrospective cohort study of 6320 procedures.

Aim  To determine whether mortality following percutaneous coronary intervention vs. coronary bypass grafting varies according to whether or not patients have diabetes.