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.

Outcomes following coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in the stent era: a prospective study of all 9890 consecutive patients operated on in Scotland over a two year period.

OBJECTIVE: To determine current outcomes of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG). DESIGN: The Scottish coronary revascularisation register provided prospectively collected data on case mix and in-hospital complications for all revascularisation procedures between April 1997 and March 1999 (4775 PTCA; 5115 CABG). Linkage to routine hospital discharge and death data provided follow up information on survival and repeat revascularisation. RESULTS: Stents were used in 51% of PTCA procedures. CABG patients were older, had more severe coronary disease, and had greater comorbidity. PTCA was more likely to be undertaken as an urgent or emergency procedure. Perioperative death and urgent surgery followed 0.3% and 0.6% of PTCA procedures, respectively. Case fatality rates were higher following CABG, with 6.7% dead within two years compared with 3.4% following PTCA. PTCA was more often followed by readmission for ischaemic heart disease, repeat angiography, or revascularisation: 22.8% of patients had repeat revascularisation within two years, compared with 1.8% following CABG. CONCLUSIONS: The severity of coronary heart disease was greater than in previously published registry studies and randomised trials. Despite this, overall survival figures were comparable and repeat revascularisation rates lower, particularly following PTCA. Perioperative death and urgent surgery following PTCA were also lower. These favourable outcomes may be attributable, in part, to increased use of bail out and elective stenting.

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

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.

Use of fax facility improves decision making regarding thrombolysis in acute myocardial infarction.

BACKGROUND: Electrocardiography is the fundamental investigation for decision making regarding thrombolytic treatment in acute myocardial infarction (MI). Increasing the accuracy of ECG analysis by input from consultant staff may assist in management decisions in patients with suspected MI. AIMS: To evaluate a system whereby out of hours ECGs can be faxed to the consultant to aid in decision making regarding thrombolytic treatment. METHODS: 112 patients with suspected MI were assessed on admission by the senior house officer (SHO) who faxed to a cardiology consultant the ECG trace and a predesigned form with information on: clinical assessment of the patient; interpretation of the ECG; and views regarding administration of thrombolytic treatment including choice of agent. The consultant reviewed the information and communicated his views to the SHO. Subsequent diagnosis was recorded in all patients and the forms were analysed in regard to areas of agreement and disagreement between the SHO and the consultant. RESULTS: A diagnosis of MI was confirmed in 52 of the 112 patients (46.4%). The consultant agreed with the SHO's decision on thrombolysis in 98 patients (87.5%). The reason for disagreement in the remaining 14 patients (12.5%) was SHO misinterpretation of the ECG (10 patients) and clinical assessment (four patients). Eight patients were saved unnecessary thrombolytic treatment and four received it when they otherwise would not have. Additionally the choice of thrombolytic agent was changed in six patients from streptokinase to tissue plasminogen activator. CONCLUSION: The use of fax machine assists in decision making with regard to thrombolytic treatment and provides support to junior doctors in what can be a difficult, yet critical decision.

The interface of hypertension and ischemic heart disease.

Myocardial infarction remains the single most common cause of death in patients with essential hypertension. This becomes particularly evident when the hypertension is associated with left ventricular hypertrophy. To combat the continuing high mortality from myocardial infarction in hypertensive heart disease, however, all aspects of the relationship must be studied. Thus, addressing the interface from an epidemiological standpoint as well as from a pathological point is critical and progress in these areas as well as in areas of management are ultimately likely to lead to a fall in morbidity and mortality from ischemic heart disease in patients with hypertension.

Transcardiac echocardiography during invasive intramedullary procedures.

We performed transoesophageal echocardiography in 111 operations (110 patients) which included medullary reaming for fresh fractures of the femur and tibia, pathological lesions of the femur, and hemiarthroplasty of the hip. Embolic events of varying intensity were seen in 97 procedures and measured pulmonary responses correlated with the severity of embolic phenomena. Twenty-four out of the 25 severe embolic responses occurred while reaming pathological lesions or during cemented hemiarthroplasty of the hip and, overall, pathological lesions produced the most severe responses. Paradoxical embolisation occurred in four patients, all with pathological lesions of the femur (21%); two died. In 12 patients large coagulative masses became trapped in the heart. Extensive pulmonary thromboembolism with reamed bone and immature clot was found at post-mortem in two patients; there was severe systemic embolisation of fat and marrow in one who had a patent foramen ovale and widespread mild systemic fat embolisation in the other without associated foraminal defect. Sequential analysis of blood from the right atrium in five patients showed considerable activation of clotting cascades during reaming.

Mechanism of closed chest cardiopulmonary resuscitation investigated by transoesophageal echocardiography.

Transoesophageal echocardiography (TOE) was performed during closed chest cardiopulmonary resuscitation (CPR) in 18 subjects in cardiac arrest. Compression of all four cardiac chambers resulted in forward flow in the pulmonary and systemic circulations, retrograde pulmonary vein flow and incomplete mitral valve closure. Antegrade pulmonary vein flow and left ventricular filling occurred exclusively during the relaxation phase. These findings support the cardiac pump theory of CPR and are incompatible with the thoracic pump mechanism. TOE merits further investigation as a device to monitor and guide resuscitation efforts during CPR.

Echocardiography of transatrial embolism during cemented and uncemented hemiarthroplasty of the hip.

We performed transoesophageal echocardiography on 20 patients with femoral neck fractures randomly treated with an uncemented Austin-Moore or cemented Hastings hemiarthroplasty. Cemented arthroplasty caused greater and more prolonged embolic cascades than did uncemented arthroplasty. Some emboli were more than 3 cm in length. In some patients the cascades were associated with pulmonary hypertension, diminished oxygen tension and saturation, and the presence of fat and marrow in aspirates from the right atrium.

Assessment of the active compression-decompression device (ACD) in cardiopulmonary resuscitation using transoesophageal echocardiography.

Transoesophageal echocardiography was used to investigate the haemodynamic profile achieved during active compression-decompression cardiopulmonary resuscitation in humans. The mechanism of antegrade blood flow achieved by ACD-CPR is consistent with the cardiac pump theory. Improved right heart compression, antegrade blood flow patterns and left ventricular filling were observed in some patients during ACD-CPR.

The detection of fat embolism by transoesophageal echocardiography during reamed intramedullary nailing. A study of 24 patients with femoral and tibial fractures.

We performed transoesophageal echocardiography on 24 patients during reamed intramedullary nailing of 17 tibial and seven femoral fractures. In 14 patients there was only minimal evidence of emboli passing through the heart, but in six copious showers of small emboli (< 10 mm maximum dimension) were observed. In four other patients, there were also multiple large emboli (> 10 mm maximum dimension). Three of these patients developed fat embolism syndrome postoperatively and one died. Earlier nailing was associated with smaller quantities of emboli.