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 pound370. 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 pound141. 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 pound170. 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 pound1358. 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.

Secondhand smoke exposure and survival following acute coronary syndrome: prospective cohort study of 1261 consecutive admissions among never-smokers.

OBJECTIVE: To determine whether exposure to secondhand smoke is associated with early prognosis following acute coronary syndrome. DESIGN, SETTING AND PARTICIPANTS: We interviewed consecutive patients admitted to nine Scottish hospitals over 23 months. Information was obtained, via questionnaire, on age, sex, smoking status, postcode of residence and admission serum cotinine concentration was measured. Follow-up data were obtained from routine hospital admission and death databases. RESULTS: Of the 5815 participants, 1261 were never-smokers. Within 30 days, 50 (4%) had died and 35 (3%) had a non-fatal myocardial infarction. All-cause deaths increased from 10 (2.1%) in those with cotinine < or =0.1 ng/ml to 22 (7.5%) in those with cotinine >0.9 ng/ml (chi(2) test for trend p<0.001). This persisted after adjustment for potential confounders (cotinine >0.9 ng/ml: adjusted OR 4.80, 95% CI 1.95 to 11.83, p = 0.003). The same dose response was observed for cardiovascular deaths and death or myocardial infarction. CONCLUSIONS: Secondhand smoke exposure is associated with worse early prognosis following acute coronary syndrome. Non-smokers need to be protected from the harmful effects of secondhand smoke.

Hospital volume of throughput and periprocedural and medium-term adverse events after percutaneous coronary intervention: retrospective cohort study of all 17,417 procedures undertaken in Scotland, 1997-2003.

OBJECTIVE: To determine whether percutaneous coronary intervention (PCI) hospital volume of throughput is associated with periprocedural and medium-term events, and whether any associations are independent of differences in case mix. DESIGN: Retrospective cohort study of all PCIs undertaken in Scottish National Health Service hospitals over a six-year period. METHODS: All PCIs in Scotland during 1997-2003 were examined. Linkage to administrative databases identified events over two years' follow up. The risk of events by hospital volume at 30 days and two years was compared by using logistic regression and Cox proportional hazards models. RESULTS: Of the 17,417 PCIs, 4900 (28%) were in low-volume hospitals and 3242 (19%) in high-volume hospitals. After adjustment for case mix, there were no significant differences in risk of death or myocardial infarction. Patients treated in high-volume hospitals were less likely to require emergency surgery (adjusted odds ratio 0.18, 95% confidence interval (CI) 0.07 to 0.54, p = 0.002). Over two years, patients in high-volume hospitals were less likely to undergo surgery (adjusted hazard ratio 0.52, 95% CI 0.35 to 0.75, p = 0.001), but this was offset by an increased likelihood of further PCI. There was no net difference in coronary revascularisation or in overall events. CONCLUSION: Death and myocardial infarction were infrequent complications of PCI and did not differ significantly by volume. Emergency surgery was less common in high-volume hospitals. Over two years, patients treated in high-volume centres were as likely to undergo some form of revascularisation but less likely to undergo surgery.

Relation between coronary pressure derived collateral flow, myocardial perfusion grade, and outcome in left ventricular function after rescue percutaneous coronary intervention.

OBJECTIVE: To evaluate the relation between pressure derived coronary collateral flow (PDCF) index and angiographic TIMI (thrombolysis in myocardial infarction) myocardial perfusion (TMP) grade, angiographic collateral grade, and subsequent recovery of left ventricular function after rescue percutaneous coronary intervention (PCI) for failed reperfusion in acute myocardial infarction. METHODS: The pressure wire was used as the guidewire in 38 consecutive patients who underwent rescue PCI between December 2000 and March 2002. Follow up angiography was performed at six months. Baseline and follow up single plane ventriculograms were analysed off line by an automated edge detection technique. A linear model was fitted to assess the relation between 0.1 unit increase in PDCF and change in left ventricular regional wall motion. RESULTS: Patients with TMP 0 grade had significantly higher mean (SD) PDCF than patients with TMP 1-3 (0.30 (0.11) v 0.15 (0.07), p < 0.0001, r = -0.5). A similar relation was observed between TMP grade and coronary wedge pressure (mean (SD) 28 (16) mm Hg with TMP 0 v 9 (7) mm Hg with TMP 1-3, p = 0.001, r = -0.4). Higher PDCF was associated with increased left ventricular end diastolic pressures (0.28 (0.14) with end diastolic pressure > 20 mm Hg v 0.22 (0.09) with end diastolic pressure < 20 mm Hg, p = 0.08, r = 0.2). No correlation was observed between PDCF and Rentrops collateral grade (0.26 (0.13) with grade 0 v 0.25 (0.11) with grades 1-3, p = 0.4, r = -0.06). No linear relation existed between changes in PDCF and changes in left ventricular regional wall motion. CONCLUSION: PDCF in the setting of rescue PCI for failed reperfusion after thrombolysis does not predict improvement in left ventricular function. Increased PDCF and coronary wedge pressure in acute myocardial infarction reflect a dysfunctional microcirculation rather than good collateral protection.

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. METHODS: We used the Scottish Coronary Revascularization Register to identify all patients undergoing revascularization in Scottish NHS hospitals since 1997. We excluded single-vessel disease, left main stem stenosis, and bypass grafting performed at the same time as other operations. We used death certificate data from the Registrar General to identify all subsequent deaths. RESULTS: Of the 6320 eligible procedures, 5042 (80%) were bypass grafts and 1278 (20%) angioplasties. Overall 831 (13%) patients had diabetes with no significant difference by procedure (13% vs. 12%). A total of 382 deaths occurred over a mean follow-up of 2.3 years. Diabetic patients had a poorer prognosis following both surgery (adjusted hazards ratio (HR) 1.43, 95% confidence interval (CI) 1.08, 1.89) and percutaneous intervention (adjusted HR 2.58, 95% CI 1.43, 4.63). Among non-diabetic patients, no significant differences in mortality were detected between the two procedures. Among diabetic patients, no significant difference was detected in those with two-vessel disease. In those with impaired left ventricular function and triple-vessel disease, angioplasty was associated with a significantly higher risk of death (adjusted HR 3.58, 95% CI 1.40, 9.19). CONCLUSIONS: This is the first study to demonstrate statistically significant results that support the BARI trial findings. Our study demonstrated a significant difference for triple-vessel disease but not two-vessel disease. The former may be due to incomplete revascularization using percutaneous intervention. Our results require corroboration from randomized trials.

Rescue percutaneous coronary intervention for failed thrombolysis: results from a district general hospital.

OBJECTIVE: To assess the outcome of a policy of emergency percutaneous coronary intervention (PCI) in patients with acute myocardial infarction and electrocardiographic (ECG) evidence of failed reperfusion after thrombolysis. DESIGN: Observational study. SETTING: District general hospital. PATIENTS: A total of 109 consecutive patients with acute myocardial infarction who underwent emergency angiography and angioplasty for failed reperfusion diagnosed on the basis of standard ECG criteria. MAIN OUTCOME MEASURES: In-hospital mortality; death, infarct territory reinfarction, and reintervention by PCI or coronary artery bypass graft (CABG) during follow up; in-lab resource utilisation. RESULTS: At initial angiography, 76 patients had Thrombolysis in Myocardial Infarction (TIMI) trial 0/1 flow and 33 had TIMI 2/3 flow. Fourteen patients were in cardiogenic shock. TIMI 3 flow was established or maintained in 93 patients (85%). Overall in-hospital mortality was 9%. It was 3% in non-shock patients, 50% in shocked patients, and 40% when the procedure was unsuccessful (TIMI 0/1 flow post-procedure). Over a mean follow up of 30 months (>12 months of follow up in all patients) there were 19 further events (one death, five reinfarctions, and 13 revascularisations (nine CABG and four PCI)). The cost of rescue PCI was not significantly higher than comparable elective interventions. CONCLUSION: A policy of emergency angiography and PCI for failed reperfusion in acute myocardial infarction can be carried out in a hospital without on-site surgical backup with good medium term clinical outcomes.