Preexisting cardiovascular conditions and long-term prognosis after initial myocardial infarction: the Framingham Study

Comparing various AI approaches to traditional quantitative assessment of the myocardial perfusion in [82Rb] PET for MACE prediction

Assessing the individual risk of Major Adverse Cardiac Events (MACE) is of major importance as cardiovascular diseases remain the leading cause of death worldwide. Quantitative Myocardial Perfusion Imaging (MPI) parameters such as stress Myocardial Blood Flow (sMBF) or Myocardial Flow Reserve (MFR) constitutes the gold standard for prognosis assessment. We propose a systematic investigation of the value of Artificial Intelligence (AI) to leverage [82 Rb] Silicon PhotoMultiplier (SiPM) PET MPI for MACE prediction. We establish a general pipeline for AI model validation to assess and compare the performance of global (i.e. average of the entire MPI signal), regional (17 segments), radiomics and Convolutional Neural Network (CNN) models leveraging various MPI signals on a dataset of 234 patients. Results showed that all regional AI models significantly outperformed the global model ( p < 0.001 ), where the best AUC of 73.9% (CI 72.5-75.3) was obtained with a CNN model. A regional AI model based on MBF averages from 17 segments fed to a Logistic Regression (LR) constituted an excellent trade-off between model simplicity and performance, achieving an AUC of 73.4% (CI 72.3-74.7). A radiomics model based on intensity features revealed that the global average was the least important feature when compared to other aggregations of the MPI signal over the myocardium. We conclude that AI models can allow better personalized prognosis assessment for MACE.

Real-World Systolic and Diastolic Blood Pressure Levels and Cardiovascular Mortality in Patients With Type 2 Diabetes-Results From a Large Registry Cohort in Asia

BACKGROUND

Elevated blood pressure (BP) is associated with increased risk of cardiovascular mortality. However, there is ongoing debate whether intensive BP lowering may paradoxically increase the risk of cardiovascular disease (CVD), especially in patients with type 2 diabetes (T2D). We investigated the association of BP with risk of CVD mortality in patients with T2D.

METHODS AND RESULTS

We used data on 83 721 patients with T2D from a multi-institutional diabetes registry in Singapore from 2013 to 2019. BP was analyzed as categories and restricted cubic splines using Cox multivariable regression analysis stratified by preexisting CVD and age (<65 years versus ≥65 years). The primary outcome was CVD mortality, determined via linkage with the national registry. Among 83 721 patients with T2D (mean age 65.3 years, 50.6% women, 78.9% taking antihypertensive medications), 7.6 per 1000 person-years experienced the primary outcome. Systolic BP had a graded relationship with a significant increase in CVD mortality at levels >120 to 129 mm Hg. Diastolic BP levels >90 mm Hg were significantly associated with CVD mortality in those aged ≥65 years. In addition, diastolic BP <70 mm Hg was associated with a significantly higher risk of CVD mortality in all patients.

CONCLUSIONS

In patients with T2D, clinic systolic BP levels ≥130 mm Hg or diastolic BP levels ≥90 mm Hg are associated with higher risk of CVD mortality. Diastolic BP <70 mm Hg is also associated with the risk of adverse CVD outcomes, although reverse causality cannot be ruled out.

Prevalence of asteroid hyalosis and systemic risk factors in United States adults

BACKGROUND/OBJECTIVE

Asteroid hyalosis (AH) is an uncommon clinical entity of unknown aetiology that is associated with older age. Previous epidemiologic studies have reported various systemic and demographic risk factors for AH but remain limited due to regional constraints of their study populations. Additionally, Hispanic and Non-Hispanic black populations remain under sampled. The aim of this study is to examine the prevalence of asteroid hyalosis in the United States and identify associated factors at a national level.

SUBJECTS/METHODS

This is a population-based, cross-sectional study of 5578 subjects aged 40 and older from the 2005 to 2008 National Health and Nutrition Examination Survey (NHANES). The primary outcome measured was asteroid hyalosis on retinal imaging in any eye. Evaluated risk factors included patient demographics, medical history, body measures, serum markers, and fundus photography findings.

RESULTS

Prevalence of asteroid hyalosis was 0.86% overall, 0.86% in Caucasians, 0.79% in African-Americans, and 0.88% in Hispanics. Asteroid hyalosis was associated with older age (p < 0.0001, 95% confidence interval [CI], 0.06-0.12; odds ratio [OR], 1.09) but not ethnicity or sex. After adjusting for age, greater bodyweight (p = 0.049; 95% CI, 0.001-0.04; OR, 1.02), and history of myocardial infarction (p = 0.022; 95% CI, 0.07-1.55; OR, 2.36) were also found to be significant risk factors.

CONCLUSION

Asteroid hyalosis is a rare entity in the US associated with older age, greater body weight, and prior history of MI. A potential relationship between AH and cardiovascular disease remains plausible.

A Cost-Effectiveness Analysis of Biomarkers for Risk Prediction in Atrial Fibrillation

RATIONALE

Atrial fibrillation (AF) is associated with an increased risk of thromboembolism. This risk is currently assessed with scoring systems based on clinical characteristics. However, these tools have limited prognostic performance. Circulating biomarkers are proposed for improved prediction of major clinical events and individualization of treatments in patients with AF.

OBJECTIVE

The aim was to assess the cost-effectiveness of precision medicine (PM), i.e., the use of combined biomarkers and clinical variables, in comparison to standard of care (SOC) for risk stratification in a hypothetical cohort of AF patients at risk of stroke.

METHODS

A Markov cohort model was developed to evaluate the costs and quality-adjusted life-years (QALYs) of PM compared to SOC, over 20 years using a Canadian healthcare system perspective.

RESULTS

PM decreased the mean per-patient overall costs by 7% ($94,932 vs $102,057 [Canadian dollars], respectively) and increased the QALYs by 12% (8.77 vs 7.68 QALYs, respectively). The calculated incremental cost-effectiveness ratio was negative, indicating that PM is an economically dominant strategy. These results were robust to one-way and probabilistic sensitivity analyses.

CONCLUSION

PM compared to SOC is economically dominant and is projected to generate cost savings.

Assessing the Validity of the Criteria for the Extreme Risk Category of Atherosclerotic Cardiovascular Disease: A Nationwide Population-Based Study

Objective

To validate the criteria for the extreme risk category for atherosclerotic cardiovascular disease (ASCVD).

Methods

An observational cohort study of 35,464 individuals with established ASCVD was performed using the National Health Information Database. Incident myocardial infarction (MI), ischemic stroke, and death in patients with established ASCVD was investigated to validate the criteria for the extreme risk category of ASCVD defined as the presence of diabetes mellitus (DM), chronic kidney disease (CKD), and history of premature ASCVD.

Results

Among 35,464 patients, 77.97% of them were classified into the extreme risk group of ASCVD. A total of 28.10%, 39.61%, and 32.12% had DM, CKD, and a history of premature ASCVD, respectively. During a mean follow-up of 8.39 years, MI, ischemic stroke, and all-cause death were found in 3.87%, 8.51%, and 23.98% of participants, respectively. In multivariate analysis, patients with DM had higher risk for MI (hazard ratio [HR], 1.62; 95% confidence interval [CI], 1.45–1.81), ischemic stroke (HR, 1.39; 95% CI, 1.29–1.50), and all-cause death (HR, 1.52; 95% CI, 1.45–1.59) than those without DM. Patients with CKD had 1.56 times higher risk for MI, 1.12 times higher risk for ischemic stroke, and 1.34 times higher risk for death than those without CKD. However, the risk for MI, ischemic stroke, and all-cause death was not different between patients with and without a history of premature ASCVD.

Conclusion

DM and CKD, but not a history of premature ASCVD, could be considered as reasonable criteria of an extreme risk for ASCVD.

Prevalence of atherosclerotic cardiovascular disease and subsequent major adverse cardiovascular events in Alberta, Canada: A real-world evidence study

BACKGROUND

Atherosclerotic cardiovascular disease (ASCVD) is a leading cause of morbidity and mortality worldwide. Data from Canadian populations regarding the burden of ASCVD are limited. Therefore, we describe the 5-year period prevalence of ASCVD and subsequent major adverse cardiovascular event (MACE) outcomes among patients with ASCVD in Alberta, Canada.

METHODS

A retrospective, observational study was conducted by linking provincial health services data, vital statistics, and pharmaceutical dispenses data. Five-year period prevalence of clinical ASCVD was captured between 2011 and 2016, and a cohort of adult patients with an initial clinical ASCVD event were identified between 2012 and 2016. One-year incidence rates (IRs) of subsequent MACE outcomes were calculated as composite and individual measures. A subgroup of patients with acute myocardial infarction (AMI) as their index event was examined.

RESULTS

There were 198 573 patients (mean [standard deviation] age: 63.9 [15.6] years; 56.6% males) identified with clinical ASCVD between 2012 and 2016. Overall, the 5-year period prevalence of ASCVD in Alberta was 89.9 per 1000 persons and the 1-year IR for a primary MACE outcome was 6.15 (95% confidence interval [CI]: 6.03-6.26) per 100 person-years. Among the ASCVD cohort, 9465 had an AMI as their index event and the IR for a primary MACE outcome was 14.30 (95% CI: 13.45-15.20) per 100 person-years.

CONCLUSIONS

This study found that the prevalence of ASCVD and the rate of subsequent MACE outcomes 1 year following the initial ASCVD event are substantial, particularly among patients with an AMI. Secondary prevention strategies aimed at lowering this risk are needed for patients with ASCVD.

A Long-Term Incidence of Heart Failure and Predictors Following Newly Developed Acute Myocardial Infarction: A 10 Years Retrospective Cohort Study with Korean National Health Insurance Data

Heart failure (HF) is the major mechanism of mortality in acute myocardial infarction (AMI) during early or intermediate post-AMI period. But heart failure is one of the most common long-term complications of AMI. Applied the retrospective cohort study design with nation representative population data, this study traced the incidence of late-onset heart failure since 1 year after newly developed acute myocardial infarction and assessed its risk factors. Methods and Results: Using the Korea National Health Insurance database, 18,328 newly developed AMI patients aged 40 years or older and first hospitalized in 2010 for 3 days or more, were set up as baseline cohort (12,403). The incidence rate of AMI per 100,000 persons was 79.8 overall, and 49.6 for women and 112.3 for men. A total of 2010 (1073 men, 937 women) were newly developed with HF during 6 years following post AMI. Cumulative incidences of HF per 1000 AMI patients for a year at each time period were 37.4 in initial hospitalization, 32.3 in 1 year after discharge, and 8.9 in 1-6 years. The overall and age-specific incidence rates of HF were higher in women than men. For late-onset HF, female, medical aid, pre-existing hypertension, severity of AMI, duration of hospital stay during index admission, reperfusion treatment, and drug prescription pattern including diuretics, affected the occurrence of late-onset HF. Conclusion: With respect to late-onset HF following AMI, appropriate management including hypertension and medical aid program in addition to quality improvement of AMI treatment are required to reduce the risk of late-onset heart failure.

Residual risk for coronary heart disease events and mortality despite intensive medical management after myocardial infarction

BACKGROUND

High-intensity statins, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, and antiplatelet agents (ie, intensive medical management) reduce coronary heart disease (CHD) risk after myocardial infarction (MI).

OBJECTIVE

The objective of the study was to determine the risk of CHD events or death despite receiving intensive medical management after MI.

METHODS

We studied 16,853 United States adults with health insurance in the MarketScan and Medicare databases who underwent percutaneous coronary intervention while hospitalized for MI between January 1, 2014 and June 30, 2015 and received intensive medical management within 30 days after hospital discharge. MI, CHD, and all-cause mortality rates from 30 days after hospital discharge through December 31, 2015 were compared with 67,412 individuals in each of three groups: (1) the general MarketScan and Medicare populations, (2) with diabetes, and (3) with a CHD history.

RESULTS

Among beneficiaries intensively medically managed after their MI, recurrent MI, CHD events, and all-cause mortality rates were 47.1, 72.0, and 57.5 per 1000 person-years, respectively. The multivariable-adjusted hazard ratio (95% CI) comparing intensively medically managed beneficiaries after MI to the general population, those with diabetes, and those with a history of CHD were 8.54 (7.52-9.70), 7.40 (6.61-8.28), and 5.45 (4.92-6.05), respectively, for recurrent MI; 7.82 (7.07-8.64), 6.27 (5.74-6.86), and 4.45 (4.10-4.82), respectively, for CHD events; and 1.15 (1.05-1.25), 1.05 (0.97-1.14), and 1.06 (0.97-1.15), respectively, for all-cause mortality.

CONCLUSION

Substantial residual risk for MI and CHD events remains despite intensive medical management after MI.

Extreme Atherosclerotic Cardiovascular Disease (ASCVD) Risk Recognition

PURPOSE OF REVIEW

To distinguish extreme and very high atherosclerotic cardiovascular disease (ASCVD) event risk based on prospective epidemiological studies and clinical trial results.

RECENT FINDINGS

Clinical practice guidelines have categorized patients with either a history of one or more "clinical ASCVD" events or "coronary heart disease (CHD) risk equivalency" to be at "very high risk" for a recurrence or a first event, respectively. A 20% or greater 10-year ASCVD risk for a composite 3-point "major" atherosclerotic cardiovascular event (MACE) of non-fatal myocardial infarction (MI), non-fatal stroke, or cardiovascular death can serve as an arbitrary definition of those at "very high risk." Exclusion of stroke may underestimate risk of "hard" endpoint 10-year ASCVD risk and addition of other potential endpoints, e.g., hospital admission for unstable angina or revascularization, a 5-point composite MACE, may overinflate the risk definitions and categorization. "Extreme" risk, a descriptor for even higher morbidity and mortality potential, defines a 30% or greater 10-year 3-point MACE (ASCVD) risk. In prospective, epidemiological studies and randomized clinical trial (RCT) participants with an initial acute coronary syndrome (ACS) within several months of entry into the study meet the inclusion criteria assignment for extreme risk. In survivors beyond the first year of an ASCVD event, "extreme" risk persists when one or more comorbidities are present, including diabetes, heart failure (HF), stage 3 or higher chronic kidney disease (CKD), familial hypercholesterolemia (FH), and poorly controlled major risk factors such as hypertension and persistent tobaccoism. "Extreme" risk particularly applies to those with progressive or multiple clinical ASCVD events in the same artery, same arterial bed, or polyvascular sites, including unstable angina and transient ischemic events. Identifying asymptomatic individuals with extensive subclinical ASCVD at "extreme" risk is a challenge, as risk engine assessment may not be adequate; individuals with genetic FH or those with diabetes and Agatston coronary artery calcification (CAC) scores greater than 1000 exemplify such threatening settings and opportunities for aggressive primary prevention. Heterogeneity exists among individuals at risk for clinical ASCVD events; identifying those at "extreme" risk, a more ominous ASCVD category, associated with greater morbidity and mortality, should prompt the most effective global cardiometabolic risk reduction.

Anticoagulation Therapy for Atrial Fibrillation in Patients With Alzheimer's Disease

Background and Purpose- Direct oral anticoagulants (DOACs) are safer, at least equally efficacious, and cost-effective compared to warfarin for stroke prevention in atrial fibrillation (AF) but they remain underused, particularly in demented patients. We estimated the cost-effectiveness of DOACs compared with warfarin in patients with AF and Alzheimer's disease (AD). Methods- We constructed a microsimulation model to estimate the lifetime costs, quality-adjusted life-years (QALYs), and cost-effectiveness of anticoagulation therapy (adjusted-dose warfarin and various DOACs) in 70-year-old patients with AF and AD from a US societal perspective. We stratified patient cohorts based on stage of AD and care setting. Model parameters were estimated from secondary sources. Health benefits were measured in the number of acute health events, life-years, and QALYs gained. We classified alternatives as cost-effective using a willingness-to-pay threshold of $100 000 per QALY gained. Results- For patients with AF and AD, compared with warfarin, DOACs increase costs but also increase QALYs by reducing the risk of stroke. For mild-AD patients living in the community, edoxaban increased lifetime costs by $6603 and increased QALYs by 0.076 compared to warfarin, yielding an incremental cost-effectiveness ratio of $86 882/QALY gained. Even though DOACs increased QALYs compared with warfarin for all patient groups (ranging from 0.019 to 0.085 additional QALYs), no DOAC treatment alternative had an incremental cost-effectiveness ratio <$150 000/QALY gained for patients with moderate to severe AD. For patients living in a long-term care facility with mild AD, the DOAC with the lowest incremental cost-effectiveness ratio (rivaroxaban) costs $150 169 per QALY gained; for patients with more severe AD, the incremental cost-effectiveness ratios were higher. Conclusions- For patients with AF and mild AD living in the community, edoxaban is cost-effective compared with warfarin. Even though patients with moderate and severe AD living in the community and patients with any stage of AD living in a long-term care setting may obtain positive clinical benefits from anticoagulation treatment, DOACs are not cost-effective compared with warfarin for these populations. Compared to aspirin, no oral anticoagulation (warfarin or any DOAC) is cost effective in patients with AF and AD.

Using nationwide ‘big data’ from linked electronic health records to help improve outcomes in cardiovascular diseases: 33 studies using methods from epidemiology, informatics, economics and social science in the ClinicAl disease research using LInked Bespoke studies and Electronic health Records (CALIBER) programme

Background

Electronic health records (EHRs), when linked across primary and secondary care and curated for research use, have the potential to improve our understanding of care quality and outcomes.

Objective

To evaluate new opportunities arising from linked EHRs for improving quality of care and outcomes for patients at risk of or with coronary disease across the patient journey.

Design

Epidemiological cohort, health informatics, health economics and ethnographic approaches were used.

Setting

230 NHS hospitals and 226 general practices in England and Wales.

Participants

Up to 2 million initially healthy adults, 100,000 people with stable coronary artery disease (SCAD) and up to 300,000 patients with acute coronary syndrome.

Main outcome measures

Quality of care, fatal and non-fatal cardiovascular disease (CVD) events.

Data platform and methods

We created a novel research platform [ClinicAl disease research using LInked Bespoke studies and Electronic health Records (CALIBER)] based on linkage of four major sources of EHR data in primary care and national registries. We carried out 33 complementary studies within the CALIBER framework. We developed a web-based clinical decision support system (CDSS) in hospital chest pain clinics. We established a novel consented prognostic clinical cohort of SCAD patients.

Results

CALIBER was successfully established as a valid research platform based on linked EHR data in nearly 2 million adults with > 600 EHR phenotypes implemented on the web portal (seehttps://caliberresearch.org/portal). Despite national guidance, key opportunities for investigation and treatment were missed across the patient journey, resulting in a worse prognosis for patients in the UK compared with patients in health systems in other countries. Our novel, contemporary, high-resolution studies showed heterogeneous associations for CVD risk factors across CVDs. The CDSS did not alter the decision-making behaviour of clinicians in chest pain clinics. Prognostic models using real-world data validly discriminated risk of death and events, and were used in cost-effectiveness decision models.

Conclusions

Emerging ‘big data’ opportunities arising from the linkage of records at different stages of a patient’s journey are vital to the generation of actionable insights into the diagnosis, risk stratification and cost-effective treatment of people at risk of, or with, CVD.

Future work

The vast majority of NHS data remain inaccessible to research and this hampers efforts to improve efficiency and quality of care and to drive innovation. We propose three priority directions for further research. First, there is an urgent need to ‘unlock’ more detailed data within hospitals for the scale of the UK’s 65 million population. Second, there is a need for scaled approaches to using EHRs to design and carry out trials, and interpret the implementation of trial results. Third, large-scale, disease agnostic genetic and biological collections linked to such EHRs are required in order to deliver precision medicine and to innovate discovery.

Study registration

CALIBER studies are registered as follows: study 2 – NCT01569139, study 4 – NCT02176174 and NCT01164371, study 5 – NCT01163513, studies 6 and 7 – NCT01804439, study 8 – NCT02285322, and studies 26–29 – NCT01162187. Optimising the Management of Angina is registered as Current Controlled Trials ISRCTN54381840.

Funding

The National Institute for Health Research (NIHR) Programme Grants for Applied Research programme (RP-PG-0407-10314) (all 33 studies) and additional funding from the Wellcome Trust (study 1), Medical Research Council Partnership grant (study 3), Servier (study 16), NIHR Research Methods Fellowship funding (study 19) and NIHR Research for Patient Benefit (study 33).

Multisite artery disease: a common and challenging clinical condition calling for specific management

'Multisite' artery disease is defined as the simultaneous presence of clinically significant atherosclerotic lesions in at least two major vascular territories. The management of patients with multisite artery disease represents a common challenge in clinical practice, since they are at increased risk for both vascular and coronary surgery. Preliminary experiences suggest that percutaneous treatment may represent a promising strategy for patients with multisite artery disease. In this review, the prevalence and management of multisite artery disease are discussed with particular attention to coronary and peripheral revascularization related issues.

PREINFARCTION ANGINA AS A CLINICAL FORM OF THE ISCHEMIC PRECONDITIONING PHENOMENON

Brief episodes of myocardial ischemia initiate a cascade of endogenous mechanisms which protect the heart during further ischemic attack. This phenomenon is called an ischemic preconditioning. Preinfarction angina is a clinical model of this phenomenon. Clinical studies have demonstrated that preinfarction angina is associated with: lower incidence of cardiogenic shock, pulmonary edema, ventricular tachycardia and ventricular fibrillation, reduced infarct size, less severe left ventricular dysfunction, better results of thrombolytic therapy, less severe myocardial reperfusion injury, better hospital and long-term prognosis. There is evidence that elderly age, presence of diabetes mellitus, left ventricular hypertrophy and hypercholesterolemia do reduce the cardioprotective effect of preinfarction angina. Preinfarction angina may be an additional criterion of risk stratification in myocardial infarction patients. This review summarizes data from the literature on the most important aspects of preinfarction angina.

Neurologic complications of myocardial infarction

Cardiac disease, in particular coronary artery disease, is the leading cause of mortality in developed nations. Strokes can complicate cardiac disease - either as result of left ventricular dysfunction and associated thrombus formation or of therapy for the cardiac disease. Antiplatelet drugs and anticoagulants routinely used to treat cardiac disease increase the risk for hemorrhagic stroke.

Type and timing of heralding in ST-elevation and non-ST-elevation myocardial infarction: an analysis of prospectively collected electronic healthcare records linked to the national registry of acute coronary syndromes

AIMS

It is widely thought that ST-elevation myocardial infarction (STEMI) is more likely to occur without warning (i.e. an unanticipated event in a previously healthy person) than non-ST-elevation myocardial infarction (NSTEMI), but no large study has evaluated this using prospectively collected data. The aim of this study was to compare the evolution of atherosclerotic disease and cardiovascular risk between people going on to experience STEMI and NSTEMI.

METHODS

We identified patients experiencing STEMI and NSTEMI in the national registry of myocardial infarction for England and Wales (Myocardial Ischaemia National Audit Project), for whom linked primary care records were available in the General Practice Research Database (as part of the CALIBER collaboration). We compared the prevalence and timing of atherosclerotic disease and major cardiovascular risk factors including smoking, hypertension, diabetes, and dyslipidaemia, between patients later experiencing STEMI to those experiencing NSTEMI.

RESULTS

A total of 8174 myocardial infarction patients were included (3780 STEMI, 4394 NSTEMI). Myocardial infarction without heralding by previously diagnosed atherosclerotic disease occurred in 71% STEMI (95% CI 69-72%) and 50% NSTEMI patients (95% CI 48-51%). The proportions of myocardial infarctions with no prior atherosclerotic disease, major risk factors, or chest pain was 14% (95% CI 13-16%) in STEMI and 9% (95% CI 9-10%) in NSTEMI. The rate of heralding coronary diagnoses was particularly high in the 12 months before infarct; 4.1-times higher (95% CI 3.3-5.0) in STEMI and 3.6-times higher (95% CI 3.1-4.2) in NSTEMI compared to the rate in earlier years.

CONCLUSIONS

Acute myocardial infarction occurring without prior diagnosed coronary, cerebrovascular, or peripheral arterial disease was common, especially for STEMI. However, there was a high prevalence of risk factors or symptoms in patients without previously diagnosed disease. Better understanding of the antecedents in the year before myocardial infarction is required.

Cost-effectiveness of new oral anticoagulants compared with warfarin in preventing stroke and other cardiovascular events in patients with atrial fibrillation

OBJECTIVES

The primary objective was to assess the cost-effectiveness of new oral anticoagulants compared with warfarin in patients with nonvalvular atrial fibrillation. Secondary objectives related to assessing the cost-effectiveness of new oral anticoagulants stratified by center-specific time in therapeutic range, age, and CHADS2 score.

METHODS

Cost-effectiveness was assessed by the incremental cost per quality-adjusted life-year (QALY) gained. Analysis used a Markov cohort model that followed patients from initiation of pharmacotherapy to death. Transition probabilities were obtained from a concurrent network meta-analysis. Utility values and costs were obtained from published data. Numerous deterministic sensitivity analyses and probabilistic analysis were conducted.

RESULTS

The incremental cost per QALY gained for dabigatran 150 mg versus warfarin was $20,797. Apixaban produced equal QALYs at a higher cost. Dabigatran 110 mg and rivaroxaban were dominated by dabigatran 150 mg and apixaban. Results were sensitive to the drug costs of apixaban, the time horizon adopted, and the consequences from major and minor bleeds with dabigatran. Results varied by a center's average time in therapeutic range, a patient's CHADS2 score, and patient age, with either dabigatran 150 mg or apixaban being optimal.

CONCLUSIONS

Results were highly sensitive to patient characteristics. Rivaroxaban and dabigatran 110 mg were unlikely to be cost-effective. For different characteristics, apixaban or dabigatran 150 mg were optimal. Thus, the choice between these two options may come down to the price of apixaban and further evidence on the impact of major and minor bleeds with dabigatran.

Nifedipine retard prevents hospitalization for angina pectoris better than angiotensin-converting enzyme inhibitors in hypertensive Japanese patients with previous myocardial infarction (JMIC-B substudy)

OBJECTIVES AND BACKGROUND

We previously reported that nifedipine retard showed comparable efficacy to angiotensin-converting enzyme (ACE) inhibitors for the prevention of cardiac events in hypertensive patients with coronary artery disease during the Japan Multicenter Investigation for Cardiovascular Diseases B study. In the nifedipine group, patients with a history of myocardial infarction (MI) showed a significant reduction in hospitalization for angina pectoris compared with the ACE inhibitor group. We investigated whether this difference was related to the progression of coronary arteriosclerosis.

METHODS

To evaluate coronary arteriosclerosis, we performed coronary angiography (CAG) and a quantitative analysis of coronary angiograms.

RESULTS

The cumulative incidence of hospitalization for angina was significantly lower in the nifedipine group (log-rank test P = 0.013). The etiology of angina requiring hospitalization was determined on the basis of CAG findings. Its incidence secondary to the development of new lesions or the progression of existing lesions was significantly lower in the nifedipine group than in the ACE inhibitor group (log-rank test P = 0.042 and P = 0.028, respectively). Using quantitative coronary analysis, changes in the coronary artery luminal diameter were compared between the nifedipine and ACE inhibitor groups. The minimum coronary lumen diameter did not show a significant change in the nifedipine group, whereas it decreased significantly in the ACE inhibitor group (paired t-test P = 0.002), and there was a significant difference between the two groups by analysis of covariance (P = 0.047).

CONCLUSION

These results indicate that nifedipine more effectively prevented admission for angina pectoris by inhibiting the progression of coronary artery disease in patients with a history of MI.

Impact of metabolic syndrome on atherosclerotic burden and cardiovascular prognosis

Patients with metabolic syndrome (MS) are at increased risk of cardiovascular atherosclerosis. The aim of this study was to evaluate the impact of MS on cardiovascular prognosis in context with atherosclerotic burden. A total of 811 patients with coronary heart disease (CHD) were included and carotid and leg arteries were examined using sonographic methods. Patients with low (CHD only, n = 428, 52.8%) or high atherosclerotic burden (CHD and peripheral atherosclerosis, n=383, 47.2%) were compared. Patients with >or=3 of the following criteria: triglycerides>or=150 mg/dl, high-density lipoprotein cholesterol<40 mg/dl (men) and <50 mg/dl (women), body mass index>30 kg/m2, blood pressure>or=130/85 mm Hg, and fasting glucose>or=100 mg/dl were defined as having MS (n=349, 43.0%). Follow-up data (median 6.7 years) were available for 807 patients (99.5%), and 175 patients (21.7%) experienced cardiovascular events (myocardial infarction, death, and stroke). The presence of MS significantly increased cardiovascular events in patients with low and high atherosclerotic burden (low: MS yes 21.2%, MS no 12.9%, p=0.02; high: MS yes 34.3%, MS no 26.5%, p=0.01). MS could be identified as an independent predictor for cardiovascular events in all patients (hazard ratio 1.7, 95% confidence interval 1.3 to 2.3, p<0.0001, adjusted) and patients with high atherosclerotic burden in particular (hazard ratio 1.8, 95% confidence interval 1.2 to 2.6, p=0.005, adjusted). In conclusion, MS markedly worsens the long-term prognosis of patients with both low and high atherosclerotic burden. Moreover, patients with high atherosclerotic burden and MS should be considered a high-risk population and treated accordingly.

Low ankle-brachial index predicts an adverse 1-year outcome after acute coronary and cerebrovascular events

BACKGROUND

Low ankle-brachial Index (ABI) identifies patients with symptomatic and asymptomatic peripheral arterial disease. The aim of this study was to correlate ABI value (normal or low) with 1-year clinical outcome in patients hospitalized for acute coronary syndromes or cerebrovascular diseases (CVD).

METHODS

ABI was measured in consecutive patients hospitalized because of acute myocardial infarction, unstable angina, stroke or transient ischemic attack (TIA). An ABI lower than or equal to 0.90 was considered abnormal. The primary outcome of the study was the composite of non-fatal acute myocardial infarction, non-fatal ischemic stroke, and death from any cause during the year following the index event.

RESULTS

An abnormal ABI was found in 27.2% of 1003 patients with acute coronary syndromes, and in 33.5% of 755 patients with acute CVD. After a median follow-up of 372 days, the frequency of the primary outcome was 10.8% (57/526) in patients with abnormal ABI and 5.9% (73/1232) in patients with normal ABI [odds ratio (OR) 1.96; 95% CI 1.36-2.81]. Death was more common in patients with abnormal ABI (OR 2.05; 95% CI 1.31-3.22). Cardiovascular mortality accounted for 81.7% of overall mortality. ABI was predictive of adverse outcome after adjustment for vascular risk factors in the logistic regression analysis (OR 1.93; 95% CI 1.24-3.01). The predictive value of ABI was mainly accounted for by patients hospitalized for acute coronary syndromes (adverse outcome: 12.8% in patients with abnormal ABI and 5.9% in patients with normal ABI, OR 2.35; 95% CI 1.47-3.76).

CONCLUSIONS

An abnormal ABI can be found in one-third of patients hospitalized for acute coronary or cerebrovascular events and is a predictor of an adverse 1-year outcome.

Acute ST-segment elevation myocardial infarction and prior stroke: an analysis from the Magnesium in Coronaries (MAGIC) trial

BACKGROUND

Patients with prior stroke represent a substantial proportion of patients presenting with acute ST-segment elevation myocardial infarction (STEMI). However, the impact of prior stroke on prognosis has not been rigorously examined in the reperfusion era.

METHODS

The baseline characteristics, treatments, and clinical outcomes of patients with prior stroke enrolled in the Magnesium in Coronaries (MAGIC) trial were evaluated and compared to those of patients without prior stroke.

RESULTS

MAGIC enrolled 6213 patients with STEMI, of whom 558 (9.0%) had prior stroke. Patients with prior stroke were more likely to have a history of hypertension (88.0% vs 70.3%), diabetes (19.9% vs 14.5%), myocardial infarction (38.2% vs 25.1%), and congestive heart failure (15.6% vs 9.7%). The mean Thrombolysis in Myocardial Infarction Risk Score was higher in patients with prior stroke compared to those without prior stroke (4.37 vs 3.93, P < .0001). Patients with prior stroke were less likely to receive reperfusion therapy, even among those considered eligible at presentation (66.3% vs 80.6%, P < .0001). Compared to patients without prior stroke, inhospital stroke (3.0% vs 1.0%, P < .0001), severe congestive heart failure (23.3% vs 18.2%, P = .003), and 30-day mortality (21.0% vs 14.7%, P < .0001) were higher among patients with prior stroke. On multivariable analysis, prior stroke was independently associated with a significantly higher risk of death at 30 days (odds ratio 1.44, P = .0023).

CONCLUSIONS

Patients with prior stroke who present with STEMI are at very high risk for short-term morbidity and mortality. Aggressive treatment of these patients appears warranted.

Infrapopliteal angioplasty

Endovascular therapy for infrapopliteal vascular disease is gaining acceptance as there is growing evidence demonstrating its safety and effectiveness. It is most commonly used to treat patients with chronic critical limb ischemia (CLI) for limb salvage and wound healing. Its use to treat lifestyle altering claudication remains controversial. For the treatment of CLI, limb salvage rates with infrapopliteal percutaneous transluminal angioplasty (PTA) are high enough that these techniques are offering an alternative to bypass surgery. Current patency rates from infrapopliteal PTA can be improved further by proper patient selection, ensuring straight-line flow to the foot in at least one tibial vessel, and close patient surveillance for early reintervention. Possible future advances including the use of drug-eluting stents, cutting balloons, and aggressive antiplatelet regimens are being tested to improve clinical outcomes following endovascular interventions on the tibial arteries.

Acute coronary syndromes in patients with prior cerebrovascular events: lessons from the Euro-Heart Survey of Acute Coronary Syndromes

BACKGROUND

The aim of this study was to determine the frequency of prior cerebrovascular events (CE) among patients with an acute coronary syndrome (ACS) and to compare the clinical characteristics, clinical course, treatment, and outcomes of patients with ACS with and without a prior CE.

METHODS AND RESULTS

We prospectively enrolled 10,484 patients with ACS in 103 hospitals in 25 countries across Europe and the Mediterranean basin. A prior CE was reported in 254 of 4338 patients (5.9%) with ST elevation, 420 of 5215 patients (8.1%) without ST elevation, and 92 of 663 patients (13.9%) with an undetermined electrocardiographic pattern. In general, patients with a prior CE were older, more likely to be females and nonsmokers, more commonly had prior myocardial infarction, heart failure, bypass surgery, and were more likely to have diabetes, hypertension, and renal failure. While in the hospital, they had more heart failure, and they were more likely to receive warfarin, digoxin, diuretics and calcium-channel blockers, and less likely to receive antiplatelet agents, beta-blockers, and statins. The inhospital mortality rates were 9.1% (with a prior CE) versus 6.4% (without a prior CE) for patients with ACS with ST elevation; 5.0% versus 2.0% for patients with ACS with non-ST elevation; and 14.1% versus 10.7% for patients with ACS with undetermined electrocardiographic results. The adjusted risk (95% CI) of inhospital death for patients with a prior CE was 1.12 (0.70, 1.81), 1.79 (1.06, 3.00), and 0.92 (0.44, 1.94) for ST-elevation ACS, non-ST-elevation ACS, and ACS with undetermined electrocardiogram, respectively. The P value for interaction between prior CE and the type of ACS on outcome was.10.

CONCLUSIONS

Patients with a prior CE constitute 7.5% of patients with ACS and have high-risk features. A prior CE is associated with increased inhospital mortality, particularly in patients with with non-ST-elevation ACS.

Preconditioning the Myocardium: From Cellular Physiology to Clinical Cardiology

Yellon, Derek M., and James M. Downey. Preconditioning the Myocardium: From Cellular Physiology to Clinical Cardiology. Physiol Rev 83: 1113-1151, 2003; 10.1152/physrev.00009.2003.—The phenomenon of ischemic preconditioning, in which a period of sublethal ischemia can profoundly protect the cell from infarction during a subsequent ischemic insult, has been responsible for an enormous amount of research over the last 15 years. Ischemic preconditioning is associated with two forms of protection: a classical form lasting ∼2 h after the preconditioning ischemia followed a day later by a second window of protection lasting ∼3 days. Both types of preconditioning share similarities in that the preconditioning ischemia provokes the release of several autacoids that trigger protection by occupying cell surface receptors. Receptor occupancy activates complex signaling cascades which during the lethal ischemia converge on one or more end-effectors to mediate the protection. The end-effectors so far have eluded identification, although a number have been proposed. A range of different pharmacological agents that activate the signaling cascades at the various levels can mimic ischemic preconditioning leading to the hope that specific therapeutic agents can be designed to exploit the profound protection seen with ischemic preconditioning. This review examines, in detail, the complex mechanisms associated with both forms of preconditioning as well as discusses the possibility to exploit this phenomenon in the clinical setting. As our understanding of the mechanisms associated with preconditioning are unravelled, we believe we can look forward to the development of new therapeutic agents with novel mechanisms of action that can supplement current treatment options for patients threatened with acute myocardial infarction.

Effects of angiotensin II type 1 receptor blockade in ApoE-deficient mice with post-ischemic heart failure

We investigated in mice whether atherosclerosis exacerbates the development of post-ischemic heart failure and alters the beneficial effects of long-term angiotensin II type 1 receptor blockade in this model. ApoE-deficient (ApoE(-/-)) and C57BL/6J (C57) mice with myocardial infarction (coronary ligation) received vehicle (C57 and ApoE(-/-)) or irbesartan (Ir, 50mg/kg/d orally, C57-Ir and ApoE(-/-)-Ir). Ten months post myocardial infarction, survival rates were similar in C57 (58%) and ApoE(62%). Atherosclerosis induced no significant alteration in blood pressure, cardiac output (fluospheres), total peripheral resistance, or shortening fraction (echocardiography) but increased renal resistance (+50%, P<0.05). Chronic Ir treatment significantly improved survival to a similar extent in both C57-Ir (85%) and ApoE(-/-)-Ir (86%). It also decreased blood pressure to a similar extent in both strains (-16% and -18%, both P<0.05). In C57-Ir mice, Ir did not modify cardiac output or total peripheral resistance, but it decreased renal resistance (-28%, P<0.001) and left-ventricular weight (-28%, P<0.05). In ApoE(-/-)-Ir mice, Ir limited atherosclerotic lesions (-13%, P<0.05), increased cardiac output (+28%, P<0.05) and shortening fraction (+24%, P<0.05), and decreased total peripheral resistance (-33%, P<0.01), renal resistance (-61%, P<0.001), and left-ventricular weight (-27%, P<0.001). In conclusion, atherosclerosis does not worsen heart failure development in mice and, although the beneficial cardiovascular effects of AT1 receptor blockade are greater in ApoE(-/-) than in C57, reduction in mortality is similar in both strains.

Predictors of cardiac and noncardiac mortality among 14,697 patients with coronary heart disease

The decrease in mortality from ischemic heart disease during the last 25 years may partly reflect improvement in diagnosis and treatment of patients with coronary heart disease. These patients, therefore, are experiencing morbidity and mortality due to other causes. The aim of our study was to describe the incidence and causes of cardiac mortality (CM) and noncardiac mortality (NCM) and to identify predictive factors. A cohort of 14,697 patients with coronary heart disease was merged with the Central Population Registry to identify mortality records from 1990 to 1996. Among the 1,839 deaths, 1,055 (57.4%) were cardiac, 626 (34.0%) were noncardiac, and 158 deaths (8.6%) were due to unknown causes as classified in the International Classification of Diseases-Ninth Edition (ICD). The 3 most significant predictors were age for a 10-year increment (odds ratios 1.75 and 2.25 for CM and NCM, respectively), chronic obstructive pulmonary disease (odds ratios 1.67 and 1.71), and current smoking (odds ratios 1.29 and 1.66). A history of cancer was a predictor of NCM, but not of CM, whereas peripheral vascular disease predicted CM but not NCM. As the number of predictive factors increased from none to >or=5, the risk of NCM gradually increased from 1.9% to 15.5%. Similar predictors expose subjects with coronary disease to CM and NCM, but smoking plays a more pronounced role in the prediction of NCM, whereas past myocardial infarction, lower levels of high-density lipoprotein cholesterol, and peripheral vascular disease are mainly associated with CM. Because of the similarity of antecedent predictors, treatment of risk factors among patients with coronary heart disease should prove valuable for the prevention of all-cause mortality.

The cost effectiveness of ACE inhibitors as first-line antihypertensive therapy

BACKGROUND

Current hypertension guidelines differ in their recommendations for first-line antihypertensive therapy.

OBJECTIVE

To evaluate the cost effectiveness of ACE inhibitor therapy as antihypertensive first-line therapy as compared with conventional antihypertensive therapy with beta-adrenoceptor antagonists or diuretics.

STUDY DESIGN

Cost-effectiveness analysis based on data from randomised trials and observational studies comparing the effectiveness of ACE inhibitor and conventional antihypertensive therapy, we constructed a Markov model to compare four strategies in the management of uncomplicated hypertension: (i) prescribing ACE inhibitor therapy to all patients; (ii) prescribing conventional therapy to all patients; (iii) individualised antihypertensive therapy based on the presence or absence of left ventricular hypertrophy on electrocardiography (ECG); or (iv) individualised antihypertensive therapy based on the presence or absence of left ventricular hypertrophy on echocardiography.

METHODS

Cost data were derived from the medical literature and focus groups, and utility values were derived from patients on antihypertensive monotherapy. All costs were calculated in 1999 Canadian dollars, but are reported in US dollars according to the 1999 purchasing power parity rate for medical and healthcare. The effectiveness of ACE inhibitor therapy in the presence of left ventricular hypertrophy was derived from observational studies. The time horizon was over a lifetime.

PERSPECTIVE

Third-party payer.

PATIENTS/PARTICIPANTS

A cohort of men aged 40 years without cardiovascular comorbidity requiring antihypertensive drug therapy.

MAIN OUTCOME MEASURES AND RESULTS

In the baseline analysis, all four strategies resulted in expected discounted QALYs that differed from each other only at the third decimal point (i.e. less than 0.003). Given the uncertainties in the variable estimates and the small size of the differences, these differences are extremely small and unlikely to represent real differences. Even accepting the small gains as real, the resulting cost-effectiveness ratios are unattractively high: $US 200,000 per QALY gained for the echocardiography strategy (compared with ECG), and $US 700,000 for the "ACE inhibitor for all" strategy (compared with ECG). The incremental cost effectiveness of prescribing ACE inhibitor therapy to everybody was never less than $US 100,000/QALY in the sensitivity analysis.

CONCLUSIONS

Prescribing ACE inhibitors as antihypertensive first-line therapy in patients without cardiovascular morbidity cannot be recommended at the present time unless the acquisition costs of ACE inhibitors become substantially more attractive.

Modification of treatment strategies over a period of 14 years has markedly reduced cardiac events among post-myocardial infarction patients

Recent trends in the treatment of post-myocardial infarction (MI) patients and the factors accounting for the improvement in outcome are presented. A total of 6,602 post-MI patients (5,320 males, 1,282 females; 58.9 +/- 10.4 years of age) enrolled between 1986 and 1999 were followed up for an average of 12.6 +/- 16.3 months. The incidence of cardiac events, which included fatal and nonfatal recurrent MIs, sudden death and death by congestive heart failure, was highest (44.9 events/1,000 person year) in 1986-1987, but decreased steadily to 22.5 events/1,000 person year by 1997-1999 (Trend p<0.0001). This trend accompanied the increased use of coronary thrombolysis, percutaneous transluminal coronary angioplasty and coronary artery bypass graft surgery, increased prescription of antiplatelet agents (51.5%-83.4%), lipid-lowering agents (29.8%-52.6%) and angiotensin-converting enzyme inhibitors (5.3%-->41.0%), and reduced prescription of calcium antagonists (68.5%-41.0%) and nitrates (60.7%-->45.7%). These changes in treatment have led to a decreased incidence of angina pectoris, wall motion abnormalities and abnormal Q waves on electrocardiograms. The decline in the incidence of cardiac events among post-MI patients in the 14 years between 1986 and 1999 reflects implementation of new therapeutic modalities proven to be effective in clinical trials and in daily practice.

Rationale for the use of platelet aggregation inhibitors in PAD patients

Peripheral arterial disease (PAD) is a major risk marker for systemic ischaemic events. The understanding of PAD has moved from PAD as an organ-specific disease to PAD as the lower-limb localization of a multifocal disease, i.e. atherothrombosis. Blood platelet activation and aggregation is a common denominator in atherothrombotic events, and use of antiplatelet agents in patients with PAD can inhibit thrombus formation and reduce the occurrence of myocardial infarction (MI), ischaemic stroke (IS) and vascular death. Many studies have investigated various antiplatelet regimens for preventing acute cardiovascular events in patients with a prior ischaemic event, although many of these studies had a number of limitations. The Antiplatelet Trialists' Collaboration performed a meta-analysis of 23 stroke trials and found an average odds risk reduction of 25% for a combined endpoint of stroke, MI or vascular death. The concept of atherothrombosis as a multifocal disease was challenged by the Clopidogrel versus Aspirin in Patients at Risk of Ischaemic Events (CAPRIE) trial. This study showed an 8.7% decrease in the relative risk reduction for further atherothrombotic events with clopidogrel over aspirin (p = 0.043) for the overall population, in terms of the combined endpoint of IS, Ml or vascular death.

[Guidelines for action and diagnosis in atherothrombosis in Spain: ADA Study (Action and Diagnosis in Atherothrombosis)]

OBJECTIVE

The ADA Study was designed to know the usual action guidelines in Spain for the diagnosis and treatment in a cohort of patients who had a recent atherothrombotic event.

PATIENTS AND METHODS

Cross-sectional, observational, multicenter epidemiologic study (294 hospitals) with a total of 3,512 patients enrolled. Patients had had an atherothrombotic event in the coronary or cerebral vascular territory in the previous month or were diagnosed of symptomatic peripheral arterial disease within the last 3 months. A total of 237 investigators (155 cardiologists, 113 neurologists, and 79 vascular surgeons) participated in the study.

RESULTS

54.9% of patients in the study had a previous atherothrombotic event. Of these, 63.1% were on antithrombotic therapy; after the second episode, 2.6% of patients were on no preventive therapy. A great disparity and an excessive number of diagnostic tests was found to confirm the diagnosis of the current atherothrombotic event, which is in contrast with a small percentage of patients who had exams performed to confirm or rule out the atherothrombotic involvement in other vascular territories.

CONCLUSIONS

An appropriate protocol should be established for the diagnosis and therapy of patients with the likelihood of having clinical manifestations due to an ahterothrombotic event.

Impact of infectious burden on extent and long-term prognosis of atherosclerosis

BACKGROUND

Recent findings suggest a causative role of infections in the pathogenesis of atherosclerosis. In hypothesizing an association between infectious agents and the development of atherosclerosis, we would expect a correlation to the extent of atherosclerosis. Moreover, this effect could be multiplied by the number of pathogens to which an individual had been exposed.

METHODS AND RESULTS

In 572 patients, IgG or IgA antibodies to herpes simplex virus 1 and 2, cytomegalovirus, Epstein-Barr virus, Hemophilus influenzae, Chlamydia pneumoniae, Mycoplasma pneumoniae, and Helicobacter pylori were measured. The extent of atherosclerosis was determined by coronary angiography, carotid duplex sonography, and evaluation of the ankle-arm index. Elevated IgA antibodies against C pneumoniae (P<0.04) and IgG antibodies against H pylori (P<0.02), cytomegalovirus (P<0.05), and herpes simplex virus 2 (P<0.01) were associated with advanced atherosclerosis (> or =2 vascular regions), adjusted for age, sex, cardiovascular risk factors, and highly sensitive C-reactive protein. Infectious burden divided into 0 to 3, 4 to 5, and 6 to 8 seropositivities was significantly associated with advanced atherosclerosis, with an odds ratio (95% CI) of 1.8 (1.2 to 2.6) for 4 to 5 (P<0.01) and 2.5 (1.2 to 5.1) for 6 to 8 seropositivities (P<0.02) (adjusted). After a mean follow-up of 3.2 years, cardiovascular mortality rate was 7.0% in patients with advanced atherosclerosis and seropositive for 0 to 3 pathogens compared with 20.0% in those seropositive for 6 to 8 pathogens.

CONCLUSIONS

Our results support the hypothesis that infectious agents are involved in the development of atherosclerosis. We showed a significant association between infectious burden and the extent of atherosclerosis. Moreover, the risk for future death was increased by the number of infectious pathogens, especially in patients with advanced atherosclerosis.

[Influence of pre-infarction angina on mid-term mortality after acute myocardial infarction]

INTRODUCTION AND OBJECTIVES

Pre-infarction angina may reduce the extent of myocardial cell necrosis and improves the prognosis after myocardial infarction. The aim of this study was to analyze the total mortality six-month after acute myocardial infarction according to the presence or absence of pre-infarction angina.

METHODS

One hundred seventy-five consecutive patients with acute myocardial infarction were prospectively included, 72 (41.4%) with pre-infarction angina. They were followed for 6 months. There were 16 deaths (15.5%) in the group of patients without pre-infarction angina and 7 (9.7%) in the group with pre-infarction angina (log-rank = 1.03; p = 0.311). The hazard-risk function curves showed a higher risk of death during the entire follow-up in the group without pre-infarction angina. In the multivariate logistic regression model, the presence of pre-infarction angina does not significantly reduce the risk of death (OR = 0.43; CI 95% = 0.09-2. 22; p = 0.303). We detected a significant interaction between treatment with sulfonylureas before the infarction and the presence of pre-infarction angina (p = 0.017).

CONCLUSIONS

In this study no significant differences were observed in total mortality six months after acute myocardial infarction according to the presence of pre-infarction angina. However, the risk of death seemed to be higher in the group of patients without pre-infarction angina during the entire follow-up. A significant interaction was found between the treatment with sulfonylurea drugs before infarction and the presence of pre-infarction angina.

[The effect of pre-infarction unstable angina on the size of myocardial necrosis]

INTRODUCTION AND OBJECTIVES

Recent studies suggest that preinfarction angina (PA) might induce less myocardial necrosis. The objective of this study is to evaluate whether patients with PA have smaller myocardial infarctions.

METHODS

Patients with acute myocardial infarction of less than 12 hours since the onset symptoms were included. PA was defined as unstable angina at rest during the 7 days before the infarction. Infarct size was assessed with the area under the curve of CK-MB levels in the 24 hours following the onset of the infarct.

RESULTS

One hundred-seventy nine patients were included, 75 (41.9%) with PA. There were more men in the group with PA (89.3% vs 70.2%, p = 0.004) and a higher prevalence of ex-smokers (38.7% vs 19.2%, p = 0.006). We did not find significant differences in myocardial infarction size between both groups, but a statistically significant interaction between PA and pre-treatment with sulfonylurea drugs was noted (p = 0.050).

CONCLUSIONS

Preinfarction angina does not seem to induce less myocardial necrosis in this study. There is a significant interaction between preinfarction angina and pre-treatment with sulfonylurea drugs.

Prognostic significance of cerebrovascular disease in 11,526 chronic coronary artery disease patients. Bezafibrate Infarction Prevention (BIP) Study Group

Patients with chronic CAD and a history of cerebrovascular events were compared with patients without prior cerebrovascular events to assess the effect of these events on 5-year prognosis. Despite adjustment for older age and higher comorbidity among patients who had experienced a cerebrovascular event, a history of such an event was associated with an increased risk of 1.86 for total mortality.

Overview of atherosclerosis

Cardiovascular disease is a serious threat to both life and health, accounting for 44% of the nation's mortality and much of its morbidity. Moreover, atherosclerotic cardiovascular disease is a growing problem because of the aging population. Coronary heart disease is the most common cause of lethal atherosclerotic disease, accounting for two thirds of all deaths resulting from heart disease and 70% of all deaths in those older than 75. A 1997 estimate put the economic cost of atherosclerotic cardiovascular disease at a staggering $259 billion. Indications are that atherosclerotic cardiovascular disease is a generalized process that involves the heart, brain, and peripheral arteries. Clinical manifestations tend to coexist, and the presence of one manifestation increases the likelihood of developing others, because major risk factors tend to affect all arterial territories. Also, clinical atherosclerosis in one area may directly predispose the patient to occurrence of atherosclerosis in another vascular territory. Therefore, measures taken to prevent one clinical manifestation of atherosclerosis should prevent the others as well. Multivariate risk profiles can identify persons at risk for atherosclerotic cardiovascular disease and target them for preventive treatment. Primary preventive measures also appear to be applicable to secondary prevention. Meta-analyses of randomized trials of the efficacy of low-dose aspirin and other antiplatelet agents in persons with overt cardiovascular disease have shown reductions of approximately 25% in the incidences of subsequent myocardial infarctions, strokes, and cardiovascular mortality. Comparison of the risk profiles for atherosclerotic cardiovascular disease indicates that correction of any particular set of risk factors or prevention of any cardiovascular disease outcome prevents other atherosclerotic disease outcomes as well. The challenge for all health care professionals is to implement comprehensive preventive measures for those at high risk for initial atherosclerotic events and even more vigorous measures for those who already have the disease.

Relationship between preinfarction angina and time interval to reperfusion with thrombolytic therapy in acute myocardial infarction

This study was conducted in an attempt to clarify whether preinfarction angina has an ischemic preconditioning effect. The subjects of this study were Killip class I patients who had suffered a first acute myocardial infarction (MI) as a result of total occlusion of the proximal left anterior descending coronary artery without development of collateral vessels and multivessel coronary artery disease. All subjects achieved successful reperfusion [thrombolysis in myocardial infarction (TIMI) flow grade 3] through intracoronary thrombolysis with single-chain urokinase-type plasminogen activator (SCU-PA). Subsequently, they received the same drug therapy and remained free of reocclusion. The patients were divided into those who experienced a new onset of prodromal angina within 24 h before the onset of acute MI [PA(+) group] and those who had a sudden onset of acute MI without the preceding angina [PA(-) group]. They were further divided according to the time interval from the onset of acute MI to reperfusion (within 1 h, 1-2 h, 2-3 h, 3-4 h, and 4-7 h). In addition, the left ventricular ejection fraction (LVEF), left ventricular end-diastolic volume index (LVEDVI), and the amount of creatine kinase (CK) released (sigma CK) were compared in these 2 groups at reperfusion time. The results of this study showed that sigma CK was significantly lower in the PA(+) group than in the PA(-) group (1,850 mIU vs 3,583 mIU) when reperfusion was induced within 1 h after the onset of acute MI. When reperfusion was induced 1-2 h after the onset of acute MI, sigma CK tended to be lower in the PA(+) group than in the PA(-) group (3,677 mIU vs 5,261 mIU). Once the time to reperfusion exceeded 2 h, there was no significant difference in sigma CK between these 2 groups. On the other hand, there were no significant differences in LVEF and LVEDVI between these 2 groups at any reperfusion time. In conclusion, preinfarction angina had a preconditioning effect (reduction in sigma CK), but this effect was lost once the time interval from the onset of acute MI to reperfusion exceeded 2 h.

Effect on survival of previous angina pectoris after acute myocardial infarction

Although the present study revealed that previous angina improved in-hospital outcome, no further benefit was observed once the patients left the hospital. The worse long-term prognosis was associated with multi-vessel coronary disease in patients with previous angina.

Controversies in preconditioning

Preconditioning is an effective mean of protecting the heart against prolonged ischemia by pretreating it with a minor insult, and the present paper reviews various controversies in this highly active field of research. In many models, adenosine plays a role by triggering the activation of protein kinase C. It may work in conjunction with other agents, such as bradykinin, but the putative role of noradrenaline is uncertain. Regulation of the enzyme producing adenosine (i.e., 5'-nucleotidase) has been reported during preconditioning but, because its activity does not seem to be associated with infarct size, it is unlikely that the hydrolase plays a pivotal role. Controversial data have been published on the involvement of mitochondrial ATPase, which may be ascribed to the poor time resolution of the experiments described; however, we do not believe that either acidosis or tissue ATP are important factors in triggering preconditioning. The role of glycolysis in the preconditioning effect remains to be firmly established; opposite mechanisms are activated in low-flow and stop-flow protocols. Although species differences regarding preconditioning exist, they seem to be more of a quantitative than a qualitative nature. The phenomenon could be clinically relevant because evidence is accumulating that preconditioning may take place during bypass surgery and coronary angioplasty if longer balloon-occlusion times are used.

Clinical aspects of preconditioning and implications for the cardiac surgeon

Ischemic preconditioning is one of the most powerful means to reduce myocardial ischemic cell death in the experimental laboratory. Data are now emerging suggesting that ischemic preconditioning also can occur in the human heart. Studies performed on human myocardial biopsies, angioplasty studies, clinical studies assessing acute tolerance to angina, and some studies evaluating the effect of angina prior to myocardial infarction, lend support to the concept that the human heart can be preconditioned. The ultimate objective is to develop preconditioning-mimetic agents that can be administered prophylactically prior to the time of cardiopulmonary bypass surgery or administered to hearts that have been harvested for transplant in order to better preserve the ischemically jeopardized myocyte.

Previous angina alters in-hospital outcome in TIMI 4. A clinical correlate to preconditioning?

BACKGROUND

Ischemic preconditioning has been shown to reduce myocardial infarct size in experimental models, but its role in patients remains unclear. Angina before myocardial infarction reflects brief episodes of ischemia and may be a marker of preconditioning. As part of the Thrombolysis in Myocardial Infarction (TIMI) 4 study, we performed an analysis on the effect of a history of previous angina on in-hospital outcomes for patients with acute myocardial infarction.

METHODS AND RESULTS

Patients eligible for thrombolytic therapy were enrolled into the study. Data were collected from case report forms regarding previous history of angina, in-hospital outcome and 6-week follow-up. Two hundred eighteen patients had a history of previous angina at any time before acute myocardial infarction, and 198 patients did not have previous angina. Patients with any previous history of angina were less likely than with those without angina to experience in-hospital death (3% versus 8%) (P = .03), severe congestive heart failure (CHF) or shock (1% versus 7%, P = .006), or the combined end point of in-hospital death, severe CHF, or shock (4% versus 12%, P = .004). Moreover, patients with any history of angina were more likely to have a smaller creatine kinase (CK)-determined infarct size (119 versus 154 CK integrated units; P = .01) and were less likely to have Q waves on their ECG (57% versus 69%; P = .01). In the subset of patients who experienced angina within the 48 hours before infarction (compared with those who did not), there was a trend toward less likely in-hospital death (3% versus 6%; P = .09), a lower incidence of severe CHF or shock (1% versus 6% P = .008), a lower combined end point of death, CHF, or shock (3% versus 10%; P = .006), smaller infarct size assessed by CK (115 versus 151 CK units; P = .03), and a trend toward fewer Q-wave infarcts. However, patients with a history of previous angina did have a trend toward more recurrent ischemic pain. Of importance is that the beneficial in-hospital effects of previous angina were not dependent on angiographically visible coronary collaterals.

CONCLUSIONS

Previous angina confers a beneficial effect on in-hospital outcome after acute myocardial infarction. The reasons for this benefit are uncertain, but one potential mechanism for this observation may be ischemic preconditioning.

Does ischemic preconditioning occur in patients?

Ischemic preconditioning offers powerful protection from ischemic necrosis in a wide range of animal species, but does it occur in humans? Support for preconditioning in humans comes from several sources: studies showing increased tolerance to repetitive balloon inflations during angioplasty, some (but not all) studies suggesting that preinfarction angina confers an early beneficial effect, studies showing that patients can develop sudden tolerance to repetitive exercise- or pacing-induced ischemia, cardiothoracic studies of intermittent aortic cross-clamping showing better preservation of myocardial adenosine triphosphate and in vitro studies of isolated human trabecular muscle and isolated human ventricular myocytes that demonstrate a biology consistent with preconditioning. In the future, preconditioning or "preconditioning mimetic" agents have the potential to be applied to a wide array of cardiovascular disorders and might result in better preservation of the heart in instances of cardiopulmonary bypass, heart transplantation, angina and myocardial infarction.

Late survival after perioperative myocardial infarction complicating vascular surgery

PURPOSE

Although early death from perioperative myocardial infarction (PMI) after vascular surgery is well established, long-term outcome in patients surviving PMI is unknown. This prospective study was designed to determine cardiac outcome and survival rates in patients with symptomatic and asymptomatic nonfatal PMI associated with peripheral vascular surgery.

METHODS

During a 36-month period for 1989 to 1992, all patients undergoing vascular surgery at our institution were monitored for PMI with serial creatine kinase and myocardial band isoenzymes and electrocardiography. PMIs were classified as symptomatic (associated with chest pain, arrhythmia, congestive heart failure, or hypotension) or asymptomatic (electrocardiographic changes and/or elevated creatine kinase and myocardial band isoenzymes). Patients with PMI were then prospectively monitored and compared for late survival, with control patients undergoing vascular surgery without PMI during the same interval.

RESULTS

During the study period 1561 major peripheral vascular procedures were performed. There were 47 PMIs (3.0%). Eleven (0.7%) PMIs were fatal, 31 were nonfatal, and five other patients with PMI died during operation of non-heart-related causes. Eight of 31 patients with nonfatal PMI had a "chemical PMI" with creatine kinase and myocardial band isoenzyme elevation as the sole indicator of PMI. During follow-up (mean 27.7 months), there was a higher incidence of both subsequent myocardial infarction and coronary artery revascularization among the patients with nonfatal PMI compared with control subjects (p < 0.05); however, survival for patients with nonfatal PMI at 1 and 4 years (80% and 51%) did not differ from that of control patients (90% and 60%) (p > 0.05). Patients with "chemical PMI" had similar patterns of subsequent myocardial infarction and coronary intervention as control patients.

CONCLUSIONS

Patients surviving nonfatal PMI after peripheral vascular surgery have a higher incidence of subsequent adverse cardiac events and coronary artery revascularization than patients undergoing vascular surgery without PMI, but they have similar survival rates at 1 and 4 years. Patients in the enzyme-only PMI group have a similar outcome compared with control subjects suggesting that a perioperative "chemical MI" may not be a significant clinical event.

Predictors of nonfatal reinfarction in survivors of myocardial infarction after thrombolysis. Results of the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2) Data Base

OBJECTIVES

This study was designed to reassess the prediction of recurrent nonfatal myocardial infarction in patients recovering from acute myocardial infarction after thrombolysis.

BACKGROUND

Recurrent nonfatal myocardial infarction is a strong and independent predictor of subsequent mortality. Current knowledge of risk factors for nonfatal reinfarction is still largely based on data gathered before the advent of thrombolysis. Thus, this prospective study was planned to identify harbinger of nonfatal reinfarction in the postinfarction patients of the multicenter Grouppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2) trial.

METHODS

Predictors of nonfatal reinfarction at 6 months were analyzed by multivariate technique (Cox model) in 8,907 GISSI-2 survivors of myocardial infarction with clinical follow-up, relying on a set of prespecified variables reflecting residual ischemia, left ventricular failure or dysfunction, complex ventricular arrhythmias, comorbidity as well as demographic and historical factors.

RESULTS

The postdischarge to 6-month incidence rate of nonfatal reinfarction was 2.5%. Independent predictors of nonfatal reinfarction were cardiac ineligibility for exercise test (relative risk 2.97, 95% confidence interval [CI] 1.98 to 4.45), previous myocardial infarction (relative risk 1.70, 95% CI 1.22 to 2.36) and angina at follow-up (relative risk 1.50, 95% CI 1.10 to 2.04). On further multivariate analysis, performed in 6,580 patients with both echocardiographic and electrocardiographic monitoring data available, a history of angina emerged as an additional risk predictor (relative risk 1.58, 95% CI 1.10 to 2.25).

CONCLUSIONS

The 6-month incidence of nonfatal reinfarction is rather low in survivors of myocardial infarction after thrombolysis. Cardiac ineligibility for exercise testing and a history of coronary artery disease are risk predictors. Recurrent nonfatal infarction is not predictable by qualitative variables reflecting residual ischemia, except by postdischarge angina. Prediction of nonfatal reinfarction appears less accurate than prediction of mortality, as almost 50% of reinfarctions occur in patients without any of the identified risk factors.