Prevention Of Recurrent Myocardial Infarction Research Articles

Abstract 15027: Predicting Recurrence of Myocardial Infarction in Post-PCI Patients Using Machine Learning

Introduction: While prevention of recurrent myocardial infarction (MI) is important in the management of patients after percutaneous coronary intervention (PCI), risk stratification of MI remains a significant challenge with increasingly diverse and complex patient backgrounds. This retrospective observational study aimed to explore whether machine learning (ML) methods can predict recurrent MI after PCI using a variety of features extracted from electronic medical records (EMRs). Methods: Seven machine learning algorithms were retrospectively applied to predict recurrent MI within two years after PCI (124 cases, 4.2%) from a total of 2984 PCI cases. The imbalance in the proportion of positive and negative data was resolved by introducing misclassification costs. Basic patient information (e.g., age, sex, risk factors) and laboratory test results were used for the analysis. Feature importance was calculated to identify key factors for MI recurrence. Five-fold cross-validation was used to calculate accuracy, sensitivity, specificity, positive predictive value, and negative predictive value (NPV) for each model. Results: As shown in Figure 1a, several ML models showed excellent diagnostic accuracies in the prediction of recurrent MI, demonstrating high NPV. Although the weighting of feature importance for MI recurrence varied among ML models, infarct size (peak CK levels), increased inflammatory status, acute coronary syndrome, and traditional coronary risk factors were identified as important features for predicting recurrent MI within two years after PCI (Figure 1b). Conclusions: It is suggested that ML using EMR data is promising for predicting recurrent MI within two years after PCI. Further studies are warranted to address whether ML-based risk stratification could lead to improved clinical decision-making after PCI.

Effectiveness of physical rehabilitation on sphygmography and blood pressure

Cardiovascular Diseases (CVD) have become the leading cause of death worldwide: for no other reason as many people die every year from CVD. This problem affects low and middle-income countries to varying degrees. More than 80% of deaths from CVD occur in these countries, almost equally among men and women, however, patients who survived after Myocardial Infarction (MI) are at high risk of death. According to the main facts of the WHO, 17.9 million people died from CVD in 2016, which accounted for 31% of all deaths in the world. In this connection, it is necessary to improve medical rehabilitation and physical rehabilitation, in particular for CVD, especially on an outpatient basis. Competent physical rehabilitation and cardiac rehabilitation in patients with myocardial infarction are associated with improved survival and effectiveness of quality of life, as well as prevention of recurrent MI. There is a legislative framework FZ-No. 323 of 21.11.2011 “On the basics of health protection of citizens in the Russian Federation” concerning medical rehabilitation and “Procedure for organizing medical rehabilitation” No. 1705n of 29.12.2012. This study shows physical rehabilitation methods of health path and Nordic walking. Terrenkur is a method of sanatorium-and-spa treatment, which provides for dosed physical activity in the form of walking tours (5 km - 6 km daily at 12.00 - 13.00). Nordic walking - walking with sticks, a type of physical activity that uses a certain training methodology and walking technique with the help of specially designed sticks (5 km - 6 km daily at 12.00 - 13.00). Multiple meta-analyses showed that Cardiovascular Rehabilitation (CVR) reduces mortality in patients with coronary artery disease. Despite the recommendations and recommendations for the use of programs for patients with previous MI, patient participation in these programs remains low, which has led to the development of alternative models of medical rehabilitation.

The application of the David back concept mechanotherapy in patients survived after myocardium infarction

The medical rehabilitation in all areas of medicine is developing actively and rapidly. In cardiology, medical rehabilitation contributes to prevention of recurrent myocardial infarction and other complications in patients with myocardial infarction. The study evaluated impact of anaerobic exercise and strength rehabilitation program on hemodynamics in patients with myocardial infarction using the David back concept mechanotherapy method.

The impact of modular cardiac rehabilitation on quality of life and exercise tolerance in patients with myocardial infarction and COVID-19 infection.

Acute myocardial infarction (AMI) remains one of the leading causes of death worldwide during cardiovascular diseases. An important step in the secondary prevention of recurrent myocardial infarction is cardiac rehabilitation (CR). However, with the onset of the global COVID-19 pandemic, the CR programs in many clinics were limited due to the quarantine measures. Knowledge about the effects of CR on quality of life and exercise tolerance in AMI patients with COVID is scarce. To evaluate the use of a modular CR program on quality of life and exercise tolerance among post-AMI patients with COVID-19 recovery, and in those with no history of COVID-19 infection. This study included 118 patients with or recovering from acute myocardial infarction. They were divided into 2 groups: the first group included 86 patients, who had slight "ground-glass opacity" changes on the computed tomography (CT) scans, and the second group comprised 32 patients, who had no history of coronavirus infection or no change on CT scan of the lungs during the pandemic. The CR program was modified due to the pandemic era. Physical tolerance increased in both groups after CR 3.6 months as compared to before the CR program (duration of training in seconds (p < 0.05), a 6-minute walk test (p < 0.05), the maximal oxygen consumption (VO2max) (p < 0.05), and the metabolic equivalent of task (MET) (p < 0.05)). Similarly, quality of life measures improved in both groups. Treatment satisfaction was higher in the first group at the beginning and the end of CR. The modular CR program improves exercise capacity and quality of life with AMI and COVID-19 similar to that of patients without AMI. Patients after COVID-19 should undergo rehabilitation.

Physical rehabilitation by various methods in patients with myocardial infarction

The objectives of physical rehabilitation are restoration of the activity of the cardiovascular system, prevention of recurrent myocardial infarction and other complications, adaptation of the patient’s body, with a previous myocardial infarction, to the usual daily stress. In our study, we carried out medical rehabilitation (MR) to patients with myocardial infarction using the methods of therapeutic physical activity through terrenkur, scandinavian walking, mechanotherapy.

HIGHER RATE OF HEMORRHAGIC STROKE AMONG BLACK PATIENTS WITH HISTORY OF MYOCARDIAL INFARCTION

Emphasis has been placed on improving the long-term outcomes of patients with acute myocardial infarction (MI), including the prevention of recurrent MI, stroke, and heart failure. There is limited information on the occurrence of hemorrhagic stroke in these patients. Patients with history of MI (n

Growing Burden of Stroke, Recent Advancements in Management and Global Commitments: The Way Forward

Worldwide, cerebrovascular accidents (stroke) are the second leading cause of death and the third leading cause of disability. Strokes mainly affect individuals at the peak of their productive life. Despite its enormous impact on countries’ socio-economic development, this growing crisis has received very little attention to date.[1] In order to achieve the UN Sustainable Development Goal 3 which aims for a 30% reduction in non-communicable diseases by 2030, it requires a substantial reduction in cardiovascular diseases. Especially the secondary prevention of recurrent myocardial infarction and stroke among those with known cardiovascular disease can reduce cardiovascular mortality and morbidity. The cost-effectiveness of secondary prevention of cardiovascular disease,[2] coupled with lifestyle changes, has long been established and it is the need of the hour to apply the recent advancements in emergency management of stroke to decrease mortality, morbidity and improve the quality of life. Read more...

Clinical Characteristics and Outcomes in Young Patients With ST-Segment Elevation Myocardial Infarction After Primary Percutaneous Coronary Intervention

BackgroundThere are few published studies of ST-segment elevation myocardial infarction (STEMI) in younger individuals. The differences between these “younger” and “older” individuals may not be fully appreciated by clinicians. The aim of this study was to determine the reasons for the earlier presentation and help to identify strategies for prevention of recurrent myocardial infarction (MI) in younger patients. MethodsThe study population was a cohort of 2,419 consecutive STEMI patients who were treated with primary percutaneous coronary intervention. The median follow-up time of this retrospective study was 2.2 years. ResultsThe all-cause mortality rates in patients ≤45 years of age at 30 days, 1 and 2 years were 1.7%, 2.0% and 2.2%, respectively. These rates were lower compared with their older matched counterparts whose all-cause mortality rates were 3.3%, 4.2% and 5.5%, respectively (P = 0.010). The incidence of recurrent MI was 4.0% for all age groups combined, 5.4% for younger patients and 3.8% for older patients. The number of stents showed association with recurrent MI in older patients with a first infarction, whereas only composition factor 1 with significantly higher non–high-density lipoprotein and low-density lipoprotein values was significantly associated with recurrent MI in the younger patients. ConclusionsSTEMI patients ≤45 years of age more often had lower rates of all-cause mortality, but the risk of recurrent MI was similar to that of older patients. Regardless of triglyceride level, neither non–high-density lipoprotein nor low-density lipoprotein were independent predictors for recurrent MI during the long-term follow-up in younger patients.

Safety and Effectiveness of Statins for Prevention of Recurrent Myocardial Infarction in 12 156 Typical Older Patients: A Quasi-Experimental Study.

Background: There is limited evidence on statin risk and effectiveness for patients aged 80+. We estimated risk of recurrent myocardial infarction, muscle-related and other adverse events, and statin-related incremental costs in “real-world” older patients treated with statins versus no statins.Methods: We used primary care electronic medical records from the UK Clinical Practice Research Datalink. Subhazard ratios (competing risk of death) for myocardial infarction recurrence (primary end point), falls, fractures, ischemic stroke, and dementia, and hazard ratios (Cox) for all-cause mortality were used to compare older (60+) statin users and 1:1 propensity-score-matched controls (n = 12,156). Participants were followed-up for 10 years.Results: Mean age was 76.5±9.2 years; 45.5% were women. Statins were associated with near significant reduction in myocardial infarction recurrence (subhazard ratio = 0.84, 0.69–1.02, p = .073), with protective effect in the 60–79 age group (0.73, 0.57–0.94) but a nonsignificant result in the 80+ group (1.06, 0.78–1.44; age interaction p = .094). No significant associations were found for stroke or dementia. Data suggest an increased risk of falls (1.36, 1.17–1.60) and fractures (1.33, 1.04–1.69) in the first 2 years of treatment, particularly in the 80+ group. Treatment was associated with lower all-cause mortality. Statin use was associated with health care cost savings in the 60–79 group but higher costs in the 80+ group.Conclusions: Estimates of statin effectiveness for the prevention of recurrent myocardial infarction in patients aged 60–79 years were similar to trial results, but more evidence is needed in the older group. There may be an excess of falls and fractures in very old patients, which deserves further investigation.

Adherence to EBM guidelines in clinical practice.

Adequate and rational pharmacotherapy is an important element of rehabilitation of patients with myocardial infarction. Orders of the Ministry of Health of the Russian Federation, domestic and international guidelines, and scientific publications - all contain a complete algorithm for rational pharmacotherapy [1, 2]. These documents are based on the principles of evidence-based medicine (EBM) and help practicing physicians to carry out individualized and rational pharmacotherapy. However, clinical studies have shown low adherence of physicians to clinical guidelines. In the Russian Federation the death rate from cardiovascular diseases is higher than in developed countries. Thus, studies of the causes of high cardiovascular mortality are needed. To assess adherence of practicing physicians to principles of evidence-based medicine in treating patients after myocardial infarction at the stage of rehabilitation. A retrospective analysis of 157 cases of patients in rehabilitation after myocardial infarction for the years 2006 and 2009 was undertaken.We analyzed the list of drugs, prescribed to patients during the period of rehabilitation, drug combinations, regimens and pharmacoepidemiological parameters. We used the following rehabilitation criteria: blood pressure control, smoking cessation, and weight control. Recommendations of controlled physical activities have also been studied. Patient care was compared with the guideline recommendations. Statistical analysis was performed using the OLAP system. 65 patients with myocardial infarction received rehabilitation therapy in 2006, and 92 - in 2009. It was found, that in 2006 physicians prescribed an average of 4.5 drugs per patient, and in 2009 - 4.6 drugs per patient. The average number of cardiovascular drugs (category C of ATC classification) per patient was 2.9 in 2006, and 2.6 - in 2009. Polypharmacy was found in half of the patients.In terms of evidence-based medicine, an important element in the rehabilitation of patients is smoking cessation and normalization of body weight. Nicotine replacement therapy and prescriptions of drugs for weight loss is one of the strategies to achieve goals. According to our study, drugs for smoking cessation and overweight were not prescribed at all. In terms of evidence-based medicine, the use of beta-blockers and ACE inhibitors for a long time by all patients is an important element of secondary prevention.The frequency of prescribing of beta-blockers was 86.1% and 91.1 %% in 2006 and 2009 respectively. The frequency of prescribing of subgroup C09 "Agents acting on the renin-angiotensin system (RAAS)" was 67.7% and 44.4% in 2006 and 2009 respectively. Beta-blockers had the highest frequency of use, while the subgroup RAAS drugs were second to them.We found that the following recommendations of clinical guidelines, based on the principles of evidence-based medicine, were not followed. We found low rates of ACE inhibitors prescribing. The structure of prescribed ACE inhibitors varied in 2006 and 2009. In 2006, 58.4% of all prescriptions were for enalapril. In 2009 enalapril use decreased to 30%, while prescribing of lisinopril increased from 0 in 2006 to 13.3%. Among angiotensin II antagonists (C09C) only losartan was used in 3.1% and 1.1% of cases in 2006 and 2009, respectively. Fixed drug combinations were not used at all.The proportion of patients who had hypertension was 73.9% and 61.9 %% in 2006 and 2009, respectively. The rate of Antihypertensive use (C02), namely Guanfacine and Moxonidine was less than 2% in both 2006 and 2009.In accordance with evidence-based principles the strategy for prevention of recurrent myocardial infarction with prescription of lipid-lowering drugs was used. Lipid-lowering drugs were prescribed to 13.8% of patients in 2006 and to 82.2% of patients in 2009. Doctors used atorvastatin and simvastatin only from the list of drugs of this group. We found that in clinical practice physicians used drugs, not supported by evidence, in particular trimetazidine was frequently used. Antiarrhythmic drugs were not prescribed at all, while part of the patients had arrhythmias. Standards of rehabilitation of patients with myocardial infarction do not contain a section on pharmacotherapy and could not be used for quality assessment. Pharmacotherapy of patients aimed at secondary prevention of myocardial infarction did not fully conform to the principles of evidence-based medicine. Standards for rehabilitation after myocardial infarction require revision based on existing clinical guidelines and evidence-based medicine.

Decreased serotonin content and reduced agonist-induced aggregation in platelets of patients chronically medicated with SSRI drugs

Chronic treatment with selective serotonin reuptake inhibitors (SSRIs) reduces the risk and severity of cardiovascular diseases. SSRIs block the serotonin transporter, thereby inhibiting serotonin (5-HT) uptake into presynaptic neurons as well as into platelets where 5-HT is stored in dense granules. When 5-HT is released in response to agonists it enhances platelet aggregation induced by injury-related signals. Chronic administration of SSRIs may thus reduce platelet aggregability secondary to depletion of platelets' serotonin stores. The study included ten DSM-IV-TR major depression (MDD) and four obsessive compulsive disorder (OCD) patients and fourteen healthy untreated age- and sex-matched controls. The patients were chronically medicated (6-108 months) with various SSRIs. Platelet serotonin content was assessed in fresh samples of platelet rich plasma (PRP) using radioimmunoassay. ADP, collagen, arachidonic acid and epinephrine were used as inducers of platelet aggregation measured in PRP by turbometric method in a microplate reader. Lower platelet serotonin content (66%; p<0.05) and lower ADP, collagen or epinephrine-induced platelet aggregation (10-52%; p<0.05) were detected in PRP of SSRI-medicated patients, while no such effect was obtained with arachidonic acid. The small sample size and the co-treatment with non-SSRI drugs such as benzodiazepines. Patients chronically medicated with SSRIs exhibit lower platelet 5-HT content and reduced platelet aggregation induced by ADP, collagen and epinephrine, but not by arachidonic acid. Our observations may explain the increased bleeding risk associated with chronic SSRI treatment as well as the reported beneficial effect of SSRIs in prevention of recurrent myocardial infarction.

Erythrocytapheresis in the prevention of recurrent myocardial infarction in sickle cell disease

Erythrocytapheresis in the prevention of recurrent myocardial infarction in sickle cell disease

Primary Prevention and Health Services Delivery

Stroke remains the third leading cause of death in the US and other Western countries,1 and at least 1 population-based study found that the incidence of stroke was greater than that of acute coronary syndromes.2 Although there have been substantial falls in stroke incidence in some countries over the last 2 decades,3 a large US study found that the advances in stroke prevention during the 1990s were not associated with decreases in the rate of stroke hospitalizations or in case-fatality rates between 1993 and 1999.4 Moreover, based solely on demographic changes in the population of selected countries within the European Union, the World Health Organization predicts a 27% increase in stroke events between the years 2000 and 2025.5 The proportion of deaths attributed to stroke is even higher in Asian countries.6 Although much of stroke risk may be related to socioeconomic factors, more effective prevention strategies are critical. Several studies have contributed to the body of knowledge related to primary stroke prevention over the last year. Numerous studies support an association between elevated homocysteine levels and atherosclerotic disease.7 The B vitamins (folic acid, B12, and B6) reduce homocysteine serum levels raising the hope that treatment would be associated with reduced risk. That hope was diminished with publication of results of the Vitamin Intervention for Stroke Prevention (VISP) trial in 2004.8 Although a secondary rather than a primary stroke prevention trial, VISP had compared high- and low-dose B-vitamin supplementation and found no treatment effect on the risk of recurrent stroke (risk ratio [RR] 1.0; 95% CI, 0.8 to 1.3), or in the combined risk of any stroke, coronary heart event, or death (RR, 1.0; 95% CI, 0.8 to 1.1). The difference in homocysteine levels between treatment groups, however, was small …

The re-emergence of anticoagulation in coronary disease

The underlying pathophysiological process in acute coronary syndromes (ACS) is intracoronary thrombus formation, leading to varying degrees of occlusion of the culprit artery and the resulting clinical manifestations of ST-elevation myocardial infarction (complete occlusion) or unstable angina/non-ST-elevation myocardial infarction (partial occlusion). Given the central role that thrombin plays in the pathogenesis of ACS, antithrombin agents are an important component of treatment. Current antithrombotics, however, have important limitations. Antiplatelet agents such as aspirin or clopidogrel, alone or in combination, fail to suppress activation of the coagulation cascade and thrombin generation in patients with ACS, highlighting the need for more intensive antithrombin therapy. Use of indirect thrombin inhibitors such as the heparins (unfractionated heparin (UFH) or low-molecular weight heparins) are restricted by the need for parenteral administration, risk of thrombocytopenia, inability to inhibit fibrin-bound thrombin, and the potential for rebound activation of the coagulation cascade and further ischaemic events after discontinuation of therapy. Direct thrombin inhibitors are potent inhibitors of both free and fibrin-bound thrombin. Trials of the intravenous direct thrombin inhibitors have shown these agents to be more efficacious than UFH for the prevention of recurrent myocardial infarction with short-term (7 days) use, supporting the rationale for the further development of the direct thrombin inhibitors. The oral anticoagulants, the vitamin K antagonists (VKAs), in combination with low-dose aspirin have demonstrated superior clinical benefits compared with aspirin treatment alone when moderate-intensity anticoagulation (international normalized ratio 2–3) is achieved. Combination antithrombotic therapy with VKAs is, however, associated with an increased risk of bleeding in a relatively high proportion of patients who subsequently have to discontinue therapy, and the complexity of treatment is a significant drawback. The limitations of existing antithrombotic therapies have provided the stimulus for the development of the oral direct thrombin inhibitors. Ximelagatran, the first in this class of agents, has the potential to overcome the limitations of existing antithrombotic therapies and is currently undergoing extensive clinical evaluation in a range of indications, including ACS.

How cost-effective are new preventive strategies for cardiovascular disease?

Costs of providing a particular medical service can be measured, but it is more difficult to assess whether the service provides good value for the money spent. Rigorous trials have demonstrated the health benefits connected with interventions for treatment and prevention of cardiovascular disease (CVD), and in-depth analyses of the costs associated with many of those interventions have been performed. Careful use of terminology clearly differentiating among cost-minimization (relative costs of proved equivalent therapeutics), cost-effectiveness (lives saved or years of life added), and cost-benefit (total net effect in monetary terms) analyses is warranted. Although trials commonly assess clinical effectiveness as reductions in mortality or CVD-specific outcomes, improvement in quality of life may be equally important and is expressed in quality-adjusted life-years. Comparisons between therapies can be assessed as a cost-effectiveness ratio. Extensive cost-effectiveness studies have been conducted on many important cardiovascular therapies: (1) β-blockers and diuretics for multiple CVD outcomes, mortality, and prevention of recurrent myocardial infarction (MI); (2) statins for both primary and secondary prevention of CVD; (3) enalapril for prevention and treatment of congestive heart failure; (4) tissue plasminogen activator treatment of acute MI; (5) coronary artery bypass graft for left main, single-, and 2-vessel coronary artery disease, or severe angina; (6) physician counseling for smoking; and (7) radiofrequency ablation therapy for Wolff-Parkinson-White syndrome. Therapies considered economically attractive include (1) secondary prevention with statins in hyperlipidemia, (2) smoking cessation programs, (3) primary prevention in treatment of high blood pressure with diuretics and β-blockers, (4) primary prevention with regular exercise programs, (5) secondary prevention with cardiac rehabilitation, and (6) postinfarction treatment with β-blockers and angiotensin-converting enzyme (ACE) inhibitors. A recent cost-minimization analysis has been performed showing aspirin to be a “best buy” therapy for secondary prevention of CVD. The Ongoing Telmisartan Alone and in Combination with Ramipril Global Endpoint Trial (ONTARGET) and Telmisartan Randomized Assessment Study in ACE-I Intolerant Patients with Cardiovascular Disease (TRANSCEND) program provide potential opportunities for both cost-minimization and cost-effectiveness analyses.

Editorial: The cardiovascular disease epidemic: global, regional, local

correspondence Pascal Bovet, University Institute of Social and Preventive Medicine, Bugnon 5, 1005Lausanne, Switzerland. Fax: +41 21 314 7373; E-mail: pascal.bovet@inst.hospvd.chThe challenge of the cardiovascular disease epidemicis not whether it will occur at all in the developingcountries but whether we respond in time to telescopethe transition and avoid the huge burden in young andmiddle age adults. The question is not whether we canafford to invest in cardiovascular disease preventionin the developing countries, but whether we canafford not to (Ruth Bonita).This statement by the director for the surveillance of non-communicable diseases at the World Health Organization(WHO) forcefully summarizes critical issues related tocardiovascular disease (CVD) in developing countries: theupsurge of the CVD epidemic and the need for an urgentresponsetopreventanimpendingadditionalburdenthatcanhardly be afforded by low and middle-income countriesalready plagued with scarce resources and a large burden ofinfectious diseases. Global–regional–local interrelations arecentral to these considerations. Globalization fuels theepidemic even to the remotest communities by spreadingmany unhealthy behaviours and environments conducive toCVD. However, globalization can also provide powerfulmeans to tackle CVD at broad and local levels.The rise in CVD in developing countries can be bestunderstood in the light of the epidemiological transition(Omran 1971; Reddy & Yusuf, 1998), an evolutionaryframework linking demographical and social change todisease patterns. The rapid ageing of populations indeveloping countries is the first engine in the emergence ofCVD. This demographic transition results from improvedsanitation, nutrition and infectious disease control, partic-ularly in childhood, which accompany urbanization andindustrialization. Prolonged survival allows for longerexposure to CVD risk factors and this inevitably results inlarger total numbers of CVD cases. In addition to ageingpopulations, industrialization and urbanization also bringabout several changes in lifestyles such as sedentary habits,tobacco use and unfavourable dietary patterns, whichfurther increase the incidence of CVD and other chronicdiseases. While the mix between specific chronic diseases inpopulations, particularly cerebrovascular disease andischaemic heart disease, can differ substantially betweendeveloping countries, the shift from early transitiondiseases (infections and malnutrition) to late transitiondiseases (CVD and other chronic diseases) is rapid, largeand consistent among most developing countries (Yusufet al. 2001a, b).It is not often appreciated that the current CVD burdenin developing countries is already high. Approximately78% of the burden of non-communicable diseases and85% of the cardiovascular burden worldwide arose fromthe low- and middle-income countries in 1998 (WHO1999). Furthermore, the CVD burden is expected to furtherincrease significantly over the next decades. The combinedmorbidity and mortality burdens (expressed as disability-adjusted years of life lost) caused by ischaemic heartdisease and cerebrovascular disease in developing countriesare anticipated to rank first and fourth in 2020, com-pared with sixth and seventh in 1999 (WHO 2000a, b). Itis also often not realized, possibly because of very highmortality rates from other diseases, that age-specific deathrates from non-communicable diseases are higher indeveloping than developed countries (Murray & Lopez1996). For example, the probability of stroke death isseveral folds higher, at all ages, in Tanzania than in the UK(Walker et al. 2000).A number of factors could exacerbate the CVD epidemicin developing countries compared with its course inwestern countries. Urbanization in settings of povertydiffers from that which occurs in prosperous economies,and the vulnerability to unhealthy behaviours is likely to beincreased in a context of loose social network, stressfulwaged labour and restricted resources for public healthresponse. This points to the higher prevalence of CVD andCVD risk factors among people of low socio-economic

Calcium Antagonists in Hypertension

Calcium antagonists (or calcium channel blockers) are pharmacological agents that are widely used in clinical medicine, mostly for cardiovascular indications [1]. Early agents of this class were discovered and thought to be similar to g -blockers during laboratory investigations, but their unique pharmacological profiles and utility in many clinical conditions was recognized during the 1960s [2]. Although the first two indications approved by the US FDA were supraventricular tachycardia (verapamil, 1981) or angina pectoris (nifedipine, 1982), most prescriptions for agents in this drug class (see Table I) are currently written for hypertension. Some of these agents have established efficacy (i.e., significantly better than placebo) in other conditions, including Raynaud's syndrome, esophageal spasm, ureteral spasm (typically due to urolithiasis), migraine headache prophylaxis, pre-term labor, cancer chemotherapy, prevention of recurrent myocardial infarction, and left ventricular dysfunction of the diastolic type. Although calcium antagonists share some important pharmacological properties, there are clear and distinct differences across many of the available agents. Dividing these into "dihydropyridine or non-dihydropyridine" subclasses (see Table I) has the advantage of being a simple, dichotomous, and clinically-useful scheme [3].

Oral Anticoagulants

We read with great interest, the article by Hirsh et al 1. Hirsh J. Dalen J.E. Deykin D. Poller L. Oral anticoagulants: mechanisms of action, clinical effectiveness, and optimal therapeutic range. Chest. 1992; 102: 26S-312S PubMed Google Scholar published in the October, 1992 supplement to Chest. Their article is a useful review of oral anticoagulants and the new recommendations for anticoagulant therapy. We wish to bring your attention to some apparent confusion regarding the new standards for therapeutic ranges of oral anticoagulants. We believe the confusion resulted from the information in Tables 2 and 4. Although the text of the article discusses the standards for recommended therapeutic ranges for oral anticoagulant therapy as they appear in Table 2, at least one other publication has printed recommendations based on the information in Table 4. 2. Karpman H.L. INR—the new standard for monitoring oral anticoagulant therapy. Intern Med Alert. 1992; (Dec 15): 178-179 Google Scholar The differences between Tables 2 and 4 are in the international normalized ratio ranges for prevention of recurrent myocardial infarction and reduction of mortality post myocardial infarction.

Effect of antiplatelet or antianginal drugs on the prevention of recurrent myocardial infarction

Effect of antiplatelet or antianginal drugs on the prevention of recurrent myocardial infarction

Factors associated with recurrent myocardial infarction within one year after acute myocardial infarction

In a large population of patients (n = 3666) who were discharged from the hospital after acute myocardial infarction and followed up for 1 year, factors associated with recurrent nonfatal (n = 171) or fatal (n = 74) infarction were identified. Also, the effects of combining various end points (recurrent nonfatal or fatal infarction and other cardiac death) in multivariate analyses, a practice common in many small studies that evaluate the predictive value of various treatments or special tests, was examined. In univariate analyses, patients with nonfatal recurrent infarction did not differ with respect to age or gender from infarct-free survivors, but they more often had a history of previous myocardial infarction, congestive heart failure, angina pectoris, and diabetes; more severe pulmonary congestion was present on chest x-ray during the admission, and a non-Q wave index infarction was more frequent. Patients with either a fatal or nonfatal recurrent infarction had more angina pectoris during follow-up (55% to 60%) compared with 27% in event-free survivors and 31% in patients who died of other cardiac causes in whom this factor could be assessed before death. In multivariate analyses, historical and clinical prognostic factors were ranked differently for fatal or nonfatal reinfarction and other cardiac causes of death; angina pectoris at follow-up was highly related to recurrent infarction (fatal or nonfatal), along with a history of diabetes, and a non-Q wave index infarction. These factors were not independently related to other causes of cardiac death. When angina pectoris at follow-up was used in the multivariate analysis of recurrent infarction (fatal plus nonfatal), it was the most important factor. This finding supports the general practice of referring patients with angina pectoris during follow-up (34% of the population) for coronary angiography in an effort to identify those with severe disease who might benefit from revascularization, which is aimed at the prevention of recurrent myocardial infarction.