Verapamil use in patients with cardiovascular disease: an overview of randomized trials

In Vitro Drug Screening Using iPSC-Derived Cardiomyocytes of a Long QT-Syndrome Patient Carrying KCNQ1 & TRPM4 Dual Mutation: An Experimental Personalized Treatment

Congenital long QT syndrome is a type of inherited cardiovascular disorder characterized by prolonged QT interval. Patient often suffer from syncopal episodes, electrocardiographic abnormalities and life-threatening arrhythmia. Given the complexity of the root cause of the disease, a combination of clinical diagnosis and drug screening using patient-derived cardiomyocytes represents a more effective way to identify potential cures. We identified a long QT syndrome patient carrying a heterozygous KCNQ1 c.656G>A mutation and a heterozygous TRPM4 c.479C>T mutation. Implantation of implantable cardioverter defibrillator in combination with conventional medication demonstrated limited success in ameliorating long-QT-syndrome-related symptoms. Frequent defibrillator discharge also caused deterioration of patient quality of life. Aiming to identify better therapeutic agents and treatment strategy, we established a patient-specific iPSC line carrying the dual mutations and differentiated these patient-specific iPSCs into cardiomyocytes. We discovered that both verapamil and lidocaine substantially shortened the QT interval of the long QT syndrome patient-specific cardiomyocytes. Verapamil treatment was successful in reducing defibrillator discharge frequency of the KCNQ1/TRPM4 dual mutation patient. These results suggested that verapamil and lidocaine could be alternative therapeutic agents for long QT syndrome patients that do not respond well to conventional treatments. In conclusion, our approach indicated the usefulness of the in vitro disease model based on patient-specific iPSCs in identifying pharmacological mechanisms and drug screening. The long QT patient-specific iPSC line carrying KCNQ1/TRPM4 dual mutations also represents a tool for further understanding long QT syndrome pathogenesis.

Development of a Chiral Capillary Electrophoresis Method for the Enantioseparation of Verapamil Using Cyclodextrins as Chiral Selectors and Experimental Design Optimization

Chirality is a property of asymmetry which determines the pharmacokinetic and pharmacological profiles of optically active pharmaceuticals. Verapamil (VER), a calcium channel blocker phenylalkylamine derivative used in the treatment of cardio-vascular diseases, is a chiral compound, marketed as a racemate, although differences between the pharmacokinetic and pharmacological attributes of the enantiomers have been reported. The aim of our study was to develop a new chiral separation method for VER enantiomers by capillary electrophoresis (CE) using cyclodextrins (CDs) as chiral selectors (CSs). After an initial screening, using different native and derivatized CDs, at four pH levels, heptakis 2,3,6-tri-O-methyl-β-CD (TM-β-CD), a neutral derivatized CD, was identified as the optimum CS. For method optimization, a preliminary univariate approach was applied to characterize the influence of analytical parameters on the separation followed by a Box–Behnken experimental design to establish the optimal separation conditions. Chiral separation of enantiomers was achieved with a resolution of 1.58 in approximately 4 min; the migration order was R-VER followed by S-VER. The method analytical performance was evaluated in terms of precision, linearity, accuracy, and robustness (applying a Plackett–Burnam experimental design). The developed method was applied for the determination of VER enantiomers in pharmaceuticals. Finally, a computer modelling of VER–CD complexes was used to describe host–guest chiral recognition.

Non-ST-Segment Acute Coronary Syndromes

Acute coronary syndrome (ACS) represents an umbrella of ischemic myocardial disease and diagnoses encompassing unstable angina (UA), non-ST-elevation myocardial infarction (NSTEMI), and ST-elevation myocardial infarction (STEMI). UA and NSTEMI for all intents and purposes, share similar pathophysiology, but at increasing severity. This article focuses on the diagnosis, risk stratification, management, and strategies that impact outcomes in NSTEMI.

2018 Guidelines of the Taiwan Society of Cardiology, Taiwan Society of Emergency Medicine and Taiwan Society of Cardiovascular Interventions for the management of non ST-segment elevation acute coronary syndrome

In Taiwan, the incidence of non-ST segment elevation acute coronary syndrome (NSTE-ACS) continues to increase in recent years. The purpose of this guideline is to help health care professionals in Taiwan to use adequate tests and treatments for management of NSTE-ACS. For rapid diagnosis, in addition to history and physical examination, 0/3 h rapid diagnosis protocol with high sensitivity cardiac troponin assay is recommended in this guideline. Dual antiplatelet and anticoagulation therapies are important parts in the initial treatment. Risk stratification should be performed to identify high risk patients for early coronary angiography. Through evaluation of the coronary anatomy and other clinical factors, the decision for coronary revascularization, either by percutaneous coronary intervention or coronary artery bypass grafting, should be decided by the heart team. The duration of dual antiplatelet therapy should be given for at least 12 months after discharge. Other secondary preventive medications are also recommended for long term use.

Influenza vaccine as a coronary intervention for prevention of myocardial infarction

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality globally. Influenza is one of the leading infectious causes of morbidity and mortality globally, and evidence is accumulating that it can precipitate acute myocardial infarction (AMI). This is thought to be due to a range of factors including inflammatory release of cytokines, disruption of atherosclerotic plaques and thrombogenesis, which may acutely occlude a coronary artery. There is a large body of observational and clinical trial evidence that shows that influenza vaccine protects against AMI. Estimates of the efficacy of influenza vaccine in preventing AMI range from 15% to 45%. This is a similar range of efficacy compared with the accepted routine coronary prevention measures such as smoking cessation (32-43%), statins (19-30%) and antihypertensive therapy (17-25%). Influenza vaccine should be considered as an integral part of CVD management and prevention. While it is recommended in many guidelines for patients with CVD, rates of vaccination in risk groups aged <65 years are very low, in the range of 30%. The incorporation of vaccination into routine CVD prevention in patient care requires a clinical practice paradigm change.

Routine invasive strategies versus selective invasive strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

People with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) are managed with a combination of medical therapy, invasive angiography and revascularisation. Specifically, two approaches have evolved: either a 'routine invasive' strategy whereby all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularisation; or a 'selective invasive' (also referred to as 'conservative') strategy in which medical therapy alone is used initially, with a selection of patients for angiography based upon evidence of persistent myocardial ischaemia. Uncertainty exists as to which strategy provides the best outcomes for these patients. This Cochrane review is an update of a Cochrane review originally published in 2006, to provide a robust comparison of these two strategies in the early management of patients with UA/NSTEMI.

OBJECTIVES

To determine the benefits and harms associated with the following.1. A routine invasive versus a conservative or 'selective invasive' strategy for the management of UA/NSTEMI in the stent era.2. A routine invasive strategy with and without glycoprotein IIb/IIIa receptor antagonists versus a conservative strategy for the management of UA/NSTEMI in the stent era.

SEARCH METHODS

We searched the following databases and additional resources up to 25 August 2015: the Cochrane Central Register of Controlled Trials (CENTRAL) on the Cochrane Library, MEDLINE and EMBASE, with no language restrictions.

SELECTION CRITERIA

We included prospective randomised controlled trials (RCTs) that compared invasive with conservative or 'selective invasive' strategies in participants with acute UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

Two review authors screened the records and extracted data in duplicate. Using intention-to-treat analysis with random-effects models, we calculated summary estimates of the risk ratio (RR) with 95% confidence intervals (CIs) for the primary endpoints of all-cause death, fatal and non-fatal myocardial infarction (MI), combined all-cause death or non-fatal MI, refractory angina and re-hospitalisation. We performed further analysis of included studies based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. We assessed the heterogeneity of included trials using Pearson χ² (Chi² test) and variance (I² statistic) analysis. Using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach, we assessed the quality of the evidence and the GRADE profiler (GRADEPRO) was used to import data from Review Manager 5.3 (Review Manager) to create Summary of findings (SoF) tables.

MAIN RESULTS

Eight RCTs with a total of 8915 participants (4545 invasive strategies, 4370 conservative strategies) were eligible for inclusion. We included three new studies and 1099 additional participants in this review update. In the all-study analysis, evidence did not show appreciable risk reductions in all-cause mortality (RR 0.87, 95% CI 0.64 to 1.18; eight studies, 8915 participants; low quality evidence) and death or non-fatal MI (RR 0.93, 95% CI 0.71 to 1.2; seven studies, 7715 participants; low quality evidence) with invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. There was appreciable risk reduction in MI (RR 0.79, 95% CI 0.63 to 1.00; eight studies, 8915 participants; moderate quality evidence), refractory angina (RR 0.64, 95% CI 0.52 to 0.79; five studies, 8287 participants; moderate quality evidence) and re-hospitalisation (RR 0.77, 95% CI 0.63 to 0.94; six studies, 6921 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies also at six to 12 months follow-up.Evidence also showed increased risks in bleeding (RR 1.73, 95% CI 1.30 to 2.31; six studies, 7584 participants; moderate quality evidence) and procedure-related MI (RR 1.87, 95% CI 1.47 to 2.37; five studies, 6380 participants; moderate quality evidence) with routine invasive strategies compared to conservative (selective invasive) strategies.The low quality evidence were as a result of serious risk of bias and imprecision in the estimate of effect while moderate quality evidence was only due to serious risk of bias.

AUTHORS' CONCLUSIONS

In the all-study analysis, the evidence failed to show appreciable benefit with routine invasive strategies for unstable angina and non-ST elevation MI compared to conservative strategies in all-cause mortality and death or non-fatal MI at six to 12 months. There was evidence of risk reduction in MI, refractory angina and re-hospitalisation with routine invasive strategies compared to conservative (selective invasive) strategies at six to 12 months follow-up. However, routine invasive strategies were associated with a relatively high risk (almost double the risk) of procedure-related MI, and increased risk of bleeding complications. This systematic analysis of published RCTs supports the conclusion that, in patients with UA/NSTEMI, a selectively invasive (conservative) strategy based on clinical risk for recurrent events is the preferred management strategy.

Myocardial infarction (ST-elevation)

INTRODUCTION

About one quarter of people having an acute myocardial infarction (MI) in the USA will die of it, half of them within 1 hour of the onset of symptoms. Cardiogenic shock develops in over 5% of people surviving the first hour after an acute MI, with a mortality of 50% to 80% in the first 48 hours.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: Which treatments improve outcomes in acute MI? Which treatments improve outcomes for cardiogenic shock after MI? We searched: Medline, Embase, The Cochrane Library, and other important databases up to October 2009 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 52 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: angiotensin-converting enzyme (ACE) inhibitors, aspirin, beta-blockers, calcium channel blockers, early cardiac surgery, early invasive cardiac revascularisation, glycoprotein IIb/IIIa inhibitors, intra-aortic balloon counterpulsation, nitrates (with or without thrombolysis), positive inotropes, primary percutaneous transluminal coronary angioplasty (PTCA), pulmonary artery catheterisation, thrombolysis (with or without low molecular weight heparin, with or without unfractionated heparin), vasodilators, and ventricular assistance devices and cardiac transplantation.

Early invasive versus conservative strategies for unstable angina and non-ST elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST elevation myocardial infarction (UA/NSTEMI) two strategies are possible, either a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially, with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2008, Issue 1), MEDLINE and EMBASE were searched (1996 to February 2008) with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified five studies (7818 participants). Using intention-to-treat analysis with random-effects models, summary estimates of relative risk (RR) with 95% confidence interval (CI) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction, all-cause death or non-fatal myocardial infarction, and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using Chi(2) and variance (I(2) statistic) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy (RR 1.59, 95% CI 0.96 to 2.64). The invasive strategy did not reduce death on longer-term follow up. Myocardial infarction rates assessed at 6 to 12 months (5 trials) and 3 to 5 years (3 trials) were significantly decreased by an invasive strategy (RR 0.73, 95% CI 0.62 to 0.86; and RR 0.78, 95% CI 0.67 to 0.92 respectively). The incidence of early (< 4 month) and intermediate (6 to 12 month) refractory angina were both significantly decreased by an invasive strategy (RR 0.47, 95% CI 0.32 to 0.68; and RR 0.67, 95% CI 0.55 to 0.83 respectively), as were early and intermediate rehospitalization rates (RR 0.60, 95% CI 0.41to 0.88; and RR 0.67, 95% CI 0.61 to 0.74 respectively). The invasive strategy was associated with a two-fold increase in the RR of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the RR of (minor) bleeding with no hazard of stroke.

AUTHORS' CONCLUSIONS

Compared to a conservative strategy for UA/NSTEMI, an invasive strategy is associated with reduced rates of refractory angina and rehospitalization in the shorter term and myocardial infarction in the longer term. However, the invasive strategy is associated with a doubled risk of procedure-related heart attack and increased risk of bleeding and procedural biomarker leaks. Available data suggest that an invasive strategy may be particularly useful in those at high risk for recurrent events.

INVEST revisited: review of findings from the International Verapamil SR-Trandolapril Study

The International Verapamil SR-Trandolapril Study (INVEST), a randomized trial of 22,576 predominantly elderly patients with an average 2.7-year follow-up, compared a calcium antagonist-led strategy (verapamil SR plus trandolapril) with a beta-blocker-led strategy (atenolol plus hydrochlorothiazide) for hypertension treatment and prevention of cardiovascular outcomes in coronary artery disease patients. Patients received individualized dose and drug titration following a flexible, multi-drug, guideline-based treatment algorithm, with the objective of achieving optimal blood pressure (BP) control individualized for comorbidities (e.g., diabetes). The primary outcome (PO) was first occurrence of death (all-cause), nonfatal myocardial infarction or nonfatal stroke. The strategies resulted in significant and very similar BP reduction, with approximately 70% of patients in both strategies achieving BP control (<140/90 mmHg). Increasing number of office visits with BP in control was associated with reduced risk of the PO. Overall, there was no difference in the PO comparing the strategies; however, new-onset diabetes occurred more frequently in those assigned the atenolol strategy. This report summarizes findings from INVEST and puts them in perspective with our current state of knowledge derived from other large hypertension treatment trials. INVEST findings support that BP reduction is important for prevention of adverse cardiovascular morbidity and mortality, and selection of antihypertensive agents should be based on patient comorbidities and other risk factors (e.g., risk for diabetes) and not necessarily that any one drug be given to all.

Acute coronary syndromes: diagnosis and management, part I

The term acute coronary syndrome (ACS) refers to any group of clinical symptoms compatible with acute myocardial ischemia and includes unstable angina (UA), non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). These high-risk manifestations of coronary atherosclerosis are important causes of the use of emergency medical care and hospitalization in the United States. A quick but thorough assessment of the patient's history and findings on physical examination, electrocardiography, radiologic studies, and cardiac biomarker tests permit accurate diagnosis and aid in early risk stratification, which is essential for guiding treatment. High-risk patients with UA/NSTEMI are often treated with an early invasive strategy involving cardiac catheterization and prompt revascularization of viable myocardium at risk. Clinical outcomes can be optimized by revascularization coupled with aggressive medical therapy that includes anti-ischemic, antiplatelet, anticoagulant, and lipid-lowering drugs. Evidence-based guidelines provide recommendations for the management of ACS; however, therapeutic approaches to the management of ACS continue to evolve at a rapid pace driven by a multitude of large-scale randomized controlled trials. Thus, clinicians are frequently faced with the problem of determining which drug or therapeutic strategy will achieve the best results. This article summarizes the evidence and provides the clinician with the latest information about the pathophysiology, clinical presentation, and risk stratification of ACS and the management of UA/NSTEMI.

Acute coronary syndromes: diagnosis and management, part I

The term acute coronary syndrome (ACS) refers to any group of clinical symptoms compatible with acute myocardial ischemia and includes unstable angina (UA), non-ST-segment elevation myocardial infarction (NSTEMI), and ST-segment elevation myocardial infarction (STEMI). These high-risk manifestations of coronary atherosclerosis are important causes of the use of emergency medical care and hospitalization in the United States. A quick but thorough assessment of the patient's history and findings on physical examination, electrocardiography, radiologic studies, and cardiac biomarker tests permit accurate diagnosis and aid in early risk stratification, which is essential for guiding treatment. High-risk patients with UA/NSTEMI are often treated with an early invasive strategy involving cardiac catheterization and prompt revascularization of viable myocardium at risk. Clinical outcomes can be optimized by revascularization coupled with aggressive medical therapy that includes anti-ischemic, antiplatelet, anticoagulant, and lipid-lowering drugs. Evidence-based guidelines provide recommendations for the management of ACS; however, therapeutic approaches to the management of ACS continue to evolve at a rapid pace driven by a multitude of large-scale randomized controlled trials. Thus, clinicians are frequently faced with the problem of determining which drug or therapeutic strategy will achieve the best results. This article summarizes the evidence and provides the clinician with the latest information about the pathophysiology, clinical presentation, and risk stratification of ACS and the management of UA/NSTEMI.

Myocardial infarction (ST-elevation)

INTRODUCTION

About a quarter of people having an acute myocardial infarction (MI) in the USA will die of it, half of them within 1 hour of the onset of symptoms. Cardiogenic shock develops in over 5% of people surviving the first hour after an acute MI, with a mortality of 50-80% in the first 48 hours.

METHODS AND OUTCOMES

We conducted a systematic review and aimed to answer the following clinical questions: Which treatments improve outcomes in acute MI? Which treatments improve outcomes for cardiogenic shock after MI? We searched: Medline, Embase, The Cochrane Library, and other important databases up to August 2007 (Clinical Evidence reviews are updated periodically, please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).

RESULTS

We found 50 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.

CONCLUSIONS

In this systematic review we present information relating to the effectiveness and safety of the following interventions: angiotensin-converting enzyme (ACE) inhibitors, aspirin, beta-blockers, calcium channel blockers, early cardiac surgery, early invasive cardiac revascularisation, glycoprotein IIb/IIIa inhibitors, intra-aortic balloon counterpulsation, nitrates (with or without thrombolysis), positive inotropes, primary percutaneous transluminal coronary angioplasty (PTCA), pulmonary artery catheterisation, thrombolysis (with or without low molecular weight heparin, with or without unfractionated heparin), vasodilators, and ventricular assistance devices and cardiac transplantation.

Impact of resting heart rate on outcomes in hypertensive patients with coronary artery disease: findings from the INternational VErapamil-SR/trandolapril STudy (INVEST)

AIM

To determine the relationship between resting heart rate (RHR) and adverse outcomes in coronary artery disease (CAD) patients treated for hypertension with different RHR-lowering strategies.

METHODS AND RESULTS

Time to adverse outcomes (death, non-fatal myocardial infarction, or non-fatal-stroke) and predictive values of baseline and follow-up RHR were assessed in INternational VErapamil-SR/trandolapril STudy (INVEST) patients randomized to either a verapamil-SR (Ve) or atenolol (At)-based strategy. Higher baseline and follow-up RHR were associated with increased adverse outcome risks, with a linear relationship for baseline RHR and J-shaped relationship for follow-up RHR. Although follow-up RHR was independently associated with adverse outcomes, it added less excess risk than baseline conditions such as heart failure and diabetes. The At strategy reduced RHR more than Ve (at 24 months, 69.2 vs. 72.8 beats/min; P < 0.001), yet adverse outcomes were similar [Ve 9.67% (rate 35/1000 patient-years) vs. At 9.88% (rate 36/1000 patient-years, confidence interval 0.90-1.06, P = 0.62)]. For the same RHR, men had a higher risk than women.

CONCLUSION

Among CAD patients with hypertension, RHR predicts adverse outcomes, and on-treatment RHR is more predictive than baseline RHR. A Ve strategy is less effective than an At strategy for lowering RHR but has a similar effect on adverse outcomes.

Acute coronary syndromes: unstable angina/non-ST elevation myocardial infarction

Acute coronary syndrome is a major health problem affecting approximately 1.5 million individuals a year. Early diagnosis and appropriate evidence-based therapies improve clinical outcomes significantly. Current data suggest that an early invasive therapy may improve intermediate-term and long-term outcomes, particularly in high-risk individuals. The last few years also have seen significant advances in antiplatelet and antithrombotic therapies for the management of patients who have acute coronary syndrome.

Management of non-ST-Segment Elevation Myocardial Infarction

Non-ST-segment elevation myocardial infarction (NSTEMI) is a major cause of cardiovascular morbidity and mortality in the United States. It represents the highest risk category of non-ST-segment elevation acute coronary syndromes (NSTEACS), for which timely diagnosis and appropriate therapy are paramount to improve outcomes. Evidence-based treatment, with combination of antiplatelet and anticoagulant therapy, and with serious consideration of early coronary angiography and revascularization along with anti-ischemic medical therapy, is the mainstay of management for NSTEMI. Aggressive risk-factor control after the acute event is imperative for secondary prevention of cardiovascular events. Applying in practice the American College of Cardiology/American Heart Association (ACC/AHA) guideline recommendations results in improved outcomes.

Early invasive versus conservative strategies for unstable angina & non-ST-elevation myocardial infarction in the stent era

BACKGROUND

In patients with unstable angina and non-ST-elevation myocardial infarction (UA/NSTEMI) two strategies are possible: a routine invasive strategy where all patients undergo coronary angiography shortly after admission and, if indicated, coronary revascularization; or a conservative strategy where medical therapy alone is used initially with selection of patients for angiography based on clinical symptoms or investigational evidence of persistent myocardial ischemia.

OBJECTIVES

To determine the benefits of an invasive compared to a conservative strategy for treating UA/NSTEMI in the stent era.

SEARCH STRATEGY

The Cochrane Central Register of Controlled Trials (Issue 3 2005), MEDLINE and EMBASE were searched from 1996 to September 2005 with no language restrictions.

SELECTION CRITERIA

Included studies were prospective trials comparing invasive with conservative strategies in UA/NSTEMI.

DATA COLLECTION AND ANALYSIS

We identified 5 studies (7818 participants). Using intention-to-treat analysis with random effects models, summary estimates of relative risk (95% confidence interval [CI]) were determined for primary end-points of all-cause death, fatal and non-fatal myocardial infarction; all-cause death or non-fatal myocardial infarction; and refractory angina. Further analysis of included studies was undertaken based on whether glycoprotein IIb/IIIa receptor antagonists were used routinely. Heterogeneity was assessed using chi-square and variance (I(2)) methods.

MAIN RESULTS

In the all-study analysis, mortality during initial hospitalization showed a trend to hazard with an invasive strategy; relative risk 1.59 (95% CI 0.96 to 2.64). Mortality and myocardial infarction assessed at 2-5 years in two trials were significantly decreased by an invasive strategy with relative risk of 0.75 (95% CI 0.62 to 0.92) and 0.75 (95% CI 0.61 to 0.91) respectively. The composite end-point of death or non-fatal myocardial infarction was significantly decreased by an invasive strategy at several time points after initial hospitalization. The incidence of early (<4 months) and intermediate (6-12 months) refractory angina were both significantly decreased by an invasive strategy; relative risk 0.47 (95% CI 0.32 to 0.68) and 0.67 (95% CI 0.55 to 0.83) respectively, as were early and intermediate rehospitalization rates with relative risk 0.60 (95% CI 0.41 to 0.88) and 0.67 (95% CI 0.61 to 0.74) respectively. The invasive strategy was associated with a two-fold increase in the relative risk of peri-procedural myocardial infarction (as variably defined) and a 1.7-fold increase in the relative risk of bleeding.

AUTHORS' CONCLUSIONS

An early invasive strategy is preferable to a conservative strategy in the treatment of UA/NSTEMI.

Treatment of patients with unstable angina and non-ST elevation myocardial infarction

Emergency department (ED) management of patients who present with suspected unstable angina (UA) and non-ST elevation myocardial infarction (NSTEMI) is especially challenging. Therapies that demonstrate benefit in patients who experience proven disease may not be indicated in patients who present with suspected disease. The emergency practitioner must have a clear understanding of the benefit and harm of each therapy, allowing formulation of a simple approach to treatment selection based on disease presentation. This article reviews current literature and discusses the treatment recommendations from the American College of Cardiology (ACC) and American Heart Association (AHA) for patients who experience UA and ST elevation myocardial infarction (STEMI).

Current medical management of chronic stable angina

Severe atherosclerotic narrowing of one or more coronary arteries is responsible for myocardial ischemia and angina pectoris in most patients with stable angina. The coronary arteries of patients with stable angina also contain many more non-obstructive plaques, which are prone to rupture resulting in acute coronary syndrome (unstable angina, myocardial infarction, sudden ischemic death). Therefore, the medical management must use strategies which not only relieve symptoms and prolong angina free walking but also reduce the incidence of adverse clinical outcomes. Whether any of the approved antianginal drugs, nitrates, beta-blockers, and calcium channel blockers reduce the incidence of adverse clinical outcomes in patients with stable angina has not been studied to date. Published data shows that percutaneous coronary revascularization procedures and coronary bypass surgery are effective in relieving angina but these procedures do not reduce mortality or the incidence of myocardial infarction compared to anti-anginal drug therapy. From the available data, an initial trial of medical treatment with anti-anginal drugs and strategies to reduce adverse clinical outcomes (smoking cessation, daily aspirin, treatment of dyslipidemias and hypertension) is indicated in most patients with stable angina pectoris. The initial choice of drug will depend on the presence or absence of comorbid conditions. Patients who do not respond to medical therapy or do not wish to take anti-anginal drugs and whose life style is limited because of anginal symptoms should be offered percutaneous revascularization procedures with or without stent placement or coronary bypass surgery. New drug-coated stents hold promise but long-term data and large-scale trials assessing the continued long-term improvement in symptoms and reduction of adverse outcomes is needed before offering such devices to all patients with stable angina. Newer medical therapies such as metabolic modulators and sinus rate lowering drugs also hold promise but need further evaluation. Patients who have refractory angina despite optimal medical therapy and are not candidates for revascularization procedures may be candidates for some new techniques of enhanced external Counterpulsation, Spinal Cord Stimulation, sympathectomy or direct transmyocardial revascularization. The usefulness of these techniques, however, needs to be confirmed in large randomized trials.

Magnesium in treatment of acute myocardial infarction

Magnesium has properties of myocardial cytoprotection, the pathophysiological explanations of which in acute myocardial infarction include prevention of arrhythmia, antiplatelet effect, prevention of reperfusion injury, and coronary vasodilation. Although several studies have evaluated the role of magnesium administration in patients with acute myocardium infarction, the clinical impact of such a therapy in this condition has been controversial, largely as a result of conflicting data from randomized controlled trials. The data available to date do not favor the routine administration of intravenous magnesium in patients with myocardial infarction, but this should not preclude magnesium administration to replenish low serum magnesium concentrations or use of magnesium sulfate for treatment of torsade de pointes in patients with myocardial infarction.

Acute ischemic syndromes. Adjunctive therapy

The acute coronary syndromes (ACS) represent a heterogeneous group of patients along a continuum of risk from unstable angina to non-ST-segment elevation myocardial infarction. ACS is a term that has been used to describe the constellation of clinical symptoms that represent acute myocardial ischemia. This article reviews the adjunctive medications that are used during emergency cardiovasculare care for the early management of patients experiencing the ACS. The adjunctive therapies are divided into early immediate treatment and then subsequent management in the acute care setting.

Heart rate-lowering calcium antagonists in hypertensive post-myocardial infarction patients

OBJECTIVES

To analyse effects of a heart rate-lowering calcium antagonist in hypertensive post-myocardial infarction patients.

DESIGN AND METHODS

From three large, randomized, placebo-controlled, secondary prevention trials investigating verapamil or diltiazem (the first and second Danish Verapamil Infarction Trials and the Multicentre Diltiazem Post-Infarction Trial) data from a total of 1,325 hypertensive post-myocardial infarction patients (drugs = 667, placebo = 658) were pooled to assess effect of blinded therapy on mortality and event rates.

RESULTS

Treatment with heart rate-lowering calcium antagonists was associated with significant reduction in event rates [21.4 versus 27.4%; risk ratio (RR) = 0.76, confidence interval (CI) = 0.61 -0.95, P= 0.013]. Mortality rates in the treatment group were 15.1 versus 17.5% in the control group (RR = 0.87, CI = 0.66-1.13, P= 0.296). Among the subset of 964 hypertensive patients without pulmonary congestion, there was some reduction in mortality rate (11.3 versus 15.3% in the control group; RR = 0.72, P= 0.066) and significant reduction in event rates (18 versus 24.4% for control group; RR = 0.70, P= 0.011). In patients with pulmonary congestion and hypertension, however, calcium antagonists were associated with a 25% increase in mortality (RR = 1.25, P= 0.339), while event rate RR was 1.00. After an adjustment for significant covariates, RR for mortality in treatment versus control groups was 0.76 (P= 0.159). For event rates, RR was 0.74 (P= 0.057).

CONCLUSIONS

Heart rate-lowering calcium antagonists decrease event rates in hypertensive post-myocardial infarction patients, but only in those without pulmonary congestion.

First line drugs in chronic stable effort angina--the case for newer, longer-acting calcium channel blocking agents

The American College of Cardiology-American Heart Association Committee recommends first line beta-adrenergic blocking agents for chronic stable effort angina. This article reassesses some critical evidence that is new or could have been neglected by the Committee. In particular, the putative role of calcium channel blocking agents (CCBs) is reexamined. Additional evidence is culled from articles not cited by the Committee, together with added reference to recent trials. Safety, side-effects and tolerability are issues that are evaluated. Mortality data are reviewed with the aid of a meta-analysis of all placebo-controlled trials on long acting CCBs. The advice of the committee may need to be reconsidered in view of recent evidence on the tolerability and benefits in hypertension of newer, longer-acting, second-generation CCBs. Of the older agents, verapamil has been shown to be the best with regard to safety and efficacy. Especially in the elderly, angina is often associated with hypertension, with evidence showing dihydropyridine CCBs and beta-adrenergic blocking agents to be similarly effective. Beta-blockers may have undesirable side effects such impotence and impaired exercise ability, despite their proven protective effects in postinfarct patients and in heart failure. The choice of drug should be keyed to the needs and the pathophysiology of the individual patient.

Current status of safety and efficacy of calcium channel blockers in cardiovascular diseases: a critical analysis based on 100 studies

Recently, serious concerns have been expressed about the long-term safety of the calcium channel blockers (CCBs) as a group. Safety and efficacy are, however, ultimately linked to each other; therefore both must be evaluated especially in the therapy of angina and hypertension, the main clinical indications for CCBs. The structural, functional, and pharmacokinetic heterogeneity of CCBs means that the efficacy and dangers of one subclass, such as the short-acting dihydropyridines (DHPs), in one situation, such as unstable angina, do not necessarily apply in other clinical situations. One hundred studies are reviewed according to their methods of data collection: case series, case control, cohort, randomized controlled trials (RCTs), and meta-analyses. Large, well-designed RCTs and the meta-analyses based on these trials remain the gold standard. Observational studies, though potentially less reliable sources of information because of selection bias, may nevertheless produce hypotheses that must then be tested in RCTs. Regarding safety, both observational studies and RCTs suggest that adverse effects of CCBs may be linked to short-acting agents, specifically short-acting nifedipine. Two good studies favor the safety of verapamil, even in short-acting form. Incomplete but increasing overall evidence favors the safety of longer-acting DHPs. Heart failure remains a class contraindication to the use of all CCBs, with some exceptions. Regarding efficacy, there are positive results of RCTs with CCBs in 2 specific clinical situations, namely, verapamil in postinfarct protection in the absence of pre-existing heart failure, and 2 outcome studies on hypertension with longer acting DHPs. These results cannot automatically be applied to other clinical situations and to other CCBs. For example, there is no evidence for the safety or efficacy of DHPs used without beta blockers in postinfarct patients. In diabetic hypertensives, 2 relatively large RCTs show that the blood pressure can be reduced by DHP-based therapy in diabetics, with a reduction in hard end points. To achieve current blood pressure goals, combination therapy is almost always necessary, and in diabetics there is strong evidence that 1 essential component should be an angiotensin converting enzyme inhibitor. The future aim with CCBs must be to obtain a large database gathered from RCTs, which will give the same certainty about efficacy and safety that already holds for use of the diuretics in hypertension, beta-blockers in postmyocardial infarction patients, and the angiotensin converting enzyme inhibitors in heart failure.

The fixed combination of verapamil SR/trandolapril

Fixed verapamil SR/trandolapril combinations 180/1 mg and 180/2 mg (Tarka, Knoll AG) have a significantly superior antihypertensive effect compared to equal dosages of either agent alone. Verapamil SR/trandolapril 180/2 mg combination produces the best dose-response ratio of different dose combinations of these two drugs. Combination therapy has the most pronounced effect on blunting the early morning rise in blood pressure. Thus, verapamil SR/trandolapril combination therapy may be an appropriate treatment option in patients with moderate essential hypertension, particularly in those who have a tendency toward the early morning rise in blood pressure. The adverse effect profile of the fixed combination of verapamil SR/trandolapril includes the typical side effects of its monocompounds. The fixed combination of verapamil SR/trandolapril is also effective and safe in the treatment of hypertension in the elderly. The fixed low-dose combination therapy with verapamil SR/trandolapril 180/2 mg is a suitable treatment option for patients with moderate essential hypertension and Type 2 diabetes mellitus, because it improves parameters of carbohydrate metabolism and uricaemia and does not alter the lipid profile. The insulin-sensitising effect of angiotensin converting enzyme (ACE) inhibitor monotherapy with its theoretical risk of hypoglycaemia is completely neutralised in the combination with verapamil SR. Comparative studies have shown that the low-dose combination of verapamil SR/trandolapril may be a suitable alternative to combinations containing a thiazide diuretic or a beta-blocking agent for the long-term management of hypertensive patients for whom combination therapy is indicated. The combination of an ACE inhibitor with a non-dihydropyridine calcium channel blocker reduces proteinuria to a greater extent than either agent alone. A combination of an ACE inhibitor and a calcium channel blocker may provide additional benefit in inducing the regression of left ventricular hypertrophy. Combination therapy leads to a significant increase in left ventricular ejection fraction, improvement of wall motion index and increases exercise duration time in patients with coronary heart disease and left heart failure. It also improves the ratio of exercise to rest rate-pressure product and decreases the number of angina attacks. These findings support the hypothesis that the combination of verapamil and trandolapril might be useful in patients with attenuated left ventricular function and angina pectoris. Thus, Tarka is an effective and well-tolerated antihypertensive agent with a good safety profile and positive metabolic effects.

Calcium antagonists in the post-myocardial infarction setting

At present, the use of calcium antagonists for the secondary prevention of cardiac events following an acute myocardial infarction (MI) is not recommended. This advice is based on several large mortality studies using short-acting calcium antagonists in the absence of coronary reperfusion therapy. Even in these studies, discrepancies between the different pharmacological classes of calcium antagonists were recognised. When separated from the dihydropyridine calcium antagonists, the rate-lowering calcium antagonists, verapamil and diltiazem, do appear to provide some benefit in reduction of recurrent MI. Three large trials using verapamil post-MI demonstrated a significant reduction in reinfarction with a favourable trend towards reducing death as well. Similarly, the effects of diltiazem post-MI have been evaluated in 3 large trials. In 2 earlier trials, diltiazem lessened cardiac events in patients with nonQ-wave infarctions and those without pulmonary congestion upon presentation. Overall, there was a significant benefit in lessening reinfarction with no effect on mortality. The recently completed Incomplete Infarction Trial of European Research Collaborators Evaluating Prognosis Post-Infarction (INTERCEPT) trial found that sustained-release diltiazem given after thrombolytic therapy for acute MI lessened cardiac events by 23% (a nonsignificant difference) without worsening congestive symptoms. Overall, there is adequate data to support the use of heart-rate-lowering calcium antagonists for secondary prevention post-MI provided the patient is intolerant of beta-blocker therapy. These trials are reviewed in detail, and suggestions for clinical practice are provided in this article.

Treatment of stable angina

Severe atherosclerotic narrowing of one or more coronary arteries is responsible for myocardial ischemia and angina pectoris in most patients with stable angina pectoris. The coronary arteries of patients with stable angina also contain many nonobstructive plaques, which are prone to fissures or rupture resulting in presentation of acute coronary syndromes (unstable angina, myocardial infarction, sudden ischemic death). In addition to symptomatic relief of symptoms and an increase in angina-free walking time with antianginal drugs or revascularization procedures, the recent emphasis of treatment has been to reduce adverse clinical outcomes (coronary death and myocardial infarction). The role of smoking cessation, aspirin, treatment of elevated lipids, and treatment of high blood pressure in all patients and of beta-blockers and angiotensin-converting enzyme inhibitors in patients with diminished systolic left ventricular systolic function in reducing adverse outcomes has been well established. What is unknown, however, is whether any anti-anginal drugs (beta-blockers, long-acting nitrates, calcium channel blockers) effect adverse outcomes in patients with stable angina pectoris. Recent trials evaluated the usefulness of suppression of ambulatory ischemia in patients with stable angina pectoris, but it remains to be established whether suppression of ambulatory myocardial ischemia with antianginal agents or revascularization therapy is superior to pharmacologic therapy targeting symptom relief. Patients who have refractory angina despite optimal medical treatment and are not candidates for revascularization procedures may be candidates for newer techniques of transmyocardial revascularization, enhanced external counterpulsation, spinal cord stimulation, or sympathectomy. The usefulness of these techniques, however, needs to be confirmed in large randomized clinical trials.

Ambulatory blood pressure monitoring and echocardiography--noninvasive techniques for evaluation of the hypertensive patient

Clinic blood pressure measurements have only limited ability to determine which hypertensive patients are at greatest risk of cardiovascular events. Ambulatory blood pressure monitoring allows for noninvasive measurement of blood pressure throughout the 24-hour period. This may help to clarify discrepancies between blood pressure values obtained in and out of the clinic and confirm the presence of white-coat hypertension, broadly defined as an elevated clinic blood pressure but a normal ambulatory blood pressure. Ambulatory blood pressure values have been shown to have a better relationship to cardiovascular morbidity and mortality and end-organ damage than clinic blood pressure values. Further, patients with white-coat hypertension appear to be at greater risk of cardiovascular morbidity and end-organ damage than a normotensive population, although they are at less overall risk than a hypertensive population. Hypertensive heart disease is characterized by diastolic dysfunction, increased left ventricular mass, and coronary flow abnormalities. Left ventricular hypertrophy increases the risk of coronary heart disease, congestive heart failure, stroke, ventricular arrhythmias, and sudden death. A variety of invasive and noninvasive techniques are described herein that measure left ventricular mass, diastolic function, and coronary blood flow abnormalities. Most antihypertensive treatments promote regression of left ventricular hypertrophy and reversal of diastolic dysfunction, which may decrease symptoms of congestive heart failure and improve survival.

Rationale and design of the International Verapamil SR/Trandolapril Study (INVEST): an Internet-based randomized trial in coronary artery disease patients with hypertension

OBJECTIVES

The primary objective of the International Verapamil SR/Trandolapril Study (INVEST) is to compare the risk for adverse outcomes (all-cause mortality, nonfatal myocardial infarction [MI] or nonfatal stroke) in hypertensive patients with coronary artery disease (CAD) treated with either a calcium antagonist-based or a noncalcium antagonist-based strategy.

BACKGROUND

Treatment recommendations for hypertension include initial therapy with a diuretic or beta-adrenergic blocking agent, for which reductions in morbidity and mortality are documented from randomized trials but are less than expected from epidemiologic data. For this reason, recent attention has focused on calcium antagonists or angiotensin-converting enzyme inhibitors. While these agents reduce blood pressure, outcome data from large randomized trials are lacking, but some case-control data, dominated by short-acting dihydropyridines, suggest an increased risk of cardiovascular events. These studies had methodologic limitations and did not differentiate among calcium antagonist types and formulations. Several studies differentiating among calcium antagonist types and an overview of published randomized trials show no increased risk with verapamil and suggestion for benefit in CAD patients.

METHODS

A total of 27,000 CAD patients with hypertension will be randomized at 1,500 primary care sites to receive either a calcium antagonist-based (verapamil) or beta-blocker/diuretic-based (atenolol/hydrochlorothiazide) antihypertensive care strategy. The study uses a novel, electronic "paper-less" system for direct on-screen data entry, randomization and drug distribution from a mail pharmacy linked to the coordination center via the Internet.

RESULTS

Contract negotiations with the United States and international sites are ongoing. Patients being enrolled are predominantly elderly (72% aged 60 years or older) men (54%), with either an abnormal coronary angiogram or prior MI (71%). In addition to hypertension, CAD and elderly age, most patients (89%) have one or more associated conditions (diabetes, dyslipidemia, smoking, cerebral or peripheral vascular disease, etc.) contributing to increased risk for adverse outcome. While 26% have diabetes, most of these are noninsulin dependent. Using the protocol strategies, target blood pressures (according to JNC VI) have been reached in 58% at the fourth visit, and as expected most (89%) are requiring multiple antihypertensive drugs.

CONCLUSION

The design and baseline characteristics of the initial patients recruited for a prospective, randomized, international, multicenter study comparing two therapeutic strategies to control hypertension in CAD patients are described.