Clinical trials update: The Heart Protection Study, IONA, CARISA, ENRICHD, ACUTE, ALIVE, MADIT II and REMATCH. Impact Of Nicorandil on Angina. Combination Assessment of Ranolazine In Stable Angina. ENhancing Recovery In Coronary Heart Disease patients. Assessment of Cardioversion Using Transoesophageal Echocardiography. AzimiLide post-Infarct surVival Evaluation. Randomised Evaluation of Mechanical Assistance for Treatment of Chronic Heart failure

Drug-induced QT prolongation: Concordance of preclinical anesthetized canine model in relation to published clinical observations for ten CiPA drugs

INTRODUCTION

The Comprehensive In Vitro Proarrhythmia Assay (CiPA) initiative differentiates torsadogenic risk of 28 drugs affecting ventricular repolarization based on multiple in vitro human derived ionic currents. However, a standardized prospective assessment of the electrophysiologic effects of these drugs in an integrated in vivo preclinical cardiovascular model is lacking. This study questioned whether QTc interval prolongation in a preclinical in vivo model could detect clinically reported QTc prolongation and assign torsadogenic risk for ten CiPA drugs.

METHODS

An acute intravenous administered ascending dose anesthetized dog cardiovascular model was used to assess QTc prolongation along with other electrocardiographic (PR, QRS intervals) and hemodynamic (heart rate, blood pressures, left ventricular contractility) parameters at plasma concentrations spanning and exceeding clinical exposures. hERG current block potency was characterized using IC₅₀ values from automated patch clamp.

RESULTS

All eight drugs eliciting clinical QTc prolongation also delayed repolarization in anesthetized dogs at plasma concentrations within four-fold clinical exposures. In vitro QTc safety margins (defined based on clinical C_max values/plasma concentrations eliciting statistically significant QTc prolongation in dogs) were lower for high vs intermediate torsadogenic risk drugs. In comparison, hERG IC₁₀ values represented as total drug concentrations were better predictors of preclinical QTc prolongation than hERG IC₅₀ values.

CONCLUSION

There was good concordance for QTc prolongation in the anesthetized dog model and clinical torsadogenic risk assignment. QTc assessment in the anesthetized dog remains a valuable part of a more comprehensive preclinical integrated risk assessment for delayed repolarization and torsadogenic risk as part of a global cardiovascular evaluation.

Psychological interventions for coronary heart disease

BACKGROUND

Coronary heart disease (CHD) is the most common cause of death globally, although mortality rates are falling. Psychological symptoms are prevalent for people with CHD, and many psychological treatments are offered following cardiac events or procedures with the aim of improving health and outcomes. This is an update of a Cochrane systematic review previously published in 2011.

OBJECTIVES

To assess the effectiveness of psychological interventions (alone or with cardiac rehabilitation) compared with usual care (including cardiac rehabilitation where available) for people with CHD on total mortality and cardiac mortality; cardiac morbidity; and participant-reported psychological outcomes of levels of depression, anxiety, and stress; and to explore potential study-level predictors of the effectiveness of psychological interventions in this population.

SEARCH METHODS

We updated the previous Cochrane Review searches by searching the following databases on 27 April 2016: CENTRAL in the Cochrane Library, MEDLINE (Ovid), Embase (Ovid), PsycINFO (Ovid), and CINAHL (EBSCO).

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of psychological interventions compared to usual care, administered by trained staff, and delivered to adults with a specific diagnosis of CHD. We selected only studies estimating the independent effect of the psychological component, and with a minimum follow-up of six months. The study population comprised of adults after: a myocardial infarction (MI), a revascularisation procedure (coronary artery bypass graft (CABG) or percutaneous coronary intervention (PCI)), and adults with angina or angiographically defined coronary artery disease (CAD). RCTs had to report at least one of the following outcomes: mortality (total- or cardiac-related); cardiac morbidity (MI, revascularisation procedures); or participant-reported levels of depression, anxiety, or stress.

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts of all references for eligibility. A lead review author extracted study data, which a second review author checked. We contacted study authors to obtain missing information.

MAIN RESULTS

This review included 35 studies which randomised 10,703 people with CHD (14 trials and 2577 participants added to this update). The population included mainly men (median 77.0%) and people post-MI (mean 65.7%) or after undergoing a revascularisation procedure (mean 27.4%). The mean age of participants within trials ranged from 53 to 67 years. Overall trial reporting was poor, with around a half omitting descriptions of randomisation sequence generation, allocation concealment procedures, or the blinding of outcome assessments. The length of follow-up ranged from six months to 10.7 years (median 12 months). Most studies (23/35) evaluated multifactorial interventions, which included therapies with multiple therapeutic components. Ten studies examined psychological interventions targeted at people with a confirmed psychopathology at baseline and two trials recruited people with a psychopathology or another selecting criterion (or both). Of the remaining 23 trials, nine studies recruited unselected participants from cardiac populations reporting some level of psychopathology (3.8% to 53% with depressive symptoms, 32% to 53% with anxiety), 10 studies did not report these characteristics, and only three studies excluded people with psychopathology.Moderate quality evidence showed no risk reduction for total mortality (risk ratio (RR) 0.90, 95% confidence interval (CI) 0.77 to 1.05; participants = 7776; studies = 23) or revascularisation procedures (RR 0.94, 95% CI 0.81 to 1.11) with psychological therapies compared to usual care. Low quality evidence found no risk reduction for non-fatal MI (RR 0.82, 95% CI 0.64 to 1.05), although there was a 21% reduction in cardiac mortality (RR 0.79, 95% CI 0.63 to 0.98). There was also low or very low quality evidence that psychological interventions improved participant-reported levels of depressive symptoms (standardised mean difference (SMD) -0.27, 95% CI -0.39 to -0.15; GRADE = low), anxiety (SMD -0.24, 95% CI -0.38 to -0.09; GRADE = low), and stress (SMD -0.56, 95% CI -0.88 to -0.24; GRADE = very low).There was substantial statistical heterogeneity for all psychological outcomes but not clinical outcomes, and there was evidence of small-study bias for one clinical outcome (cardiac mortality: Egger test P = 0.04) and one psychological outcome (anxiety: Egger test P = 0.012). Meta-regression exploring a limited number of intervention characteristics found no significant predictors of intervention effects for total mortality and cardiac mortality. For depression, psychological interventions combined with adjunct pharmacology (where deemed appropriate) for an underlying psychological disorder appeared to be more effective than interventions that did not (β = -0.51, P = 0.003). For anxiety, interventions recruiting participants with an underlying psychological disorder appeared more effective than those delivered to unselected populations (β = -0.28, P = 0.03).

AUTHORS' CONCLUSIONS

This updated Cochrane Review found that for people with CHD, there was no evidence that psychological treatments had an effect on total mortality, the risk of revascularisation procedures, or on the rate of non-fatal MI, although the rate of cardiac mortality was reduced and psychological symptoms (depression, anxiety, or stress) were alleviated; however, the GRADE assessments suggest considerable uncertainty surrounding these effects. Considerable uncertainty also remains regarding the people who would benefit most from treatment (i.e. people with or without psychological disorders at baseline) and the specific components of successful interventions. Future large-scale trials testing the effectiveness of psychological therapies are required due to the uncertainty within the evidence. Future trials would benefit from testing the impact of specific (rather than multifactorial) psychological interventions for participants with CHD, and testing the targeting of interventions on different populations (i.e. people with CHD, with or without psychopathologies).

Cardiac-Specific Deletion of the Pdha1 Gene Sensitizes Heart to Toxicological Actions of Ischemic Stress

Pyruvate dehydrogenase (PDH) plays a key role in aerobic energy metabolism and occupies a central crossroad between glycolysis and the tricarboxylic acid cycle. We generated inducible cardiac-specific PDH E1α knockout (CreER(T2)-PDH(flox/flox)) mice that demonstrated a high mortality rate. It was hypothesized that PDH modulating cardiac glucose metabolism is crucial for heart functions under normal physiological and/or stress conditions. The myocardial infarction was conducted by a ligation of the left anterior descending coronary arteries. Cardiac PDH E1α deficiency caused large myocardial infarcts size and macrophage infiltration in the hearts (P < .01 vs wild-type [WT]). Wheat germ agglutinin and Masson trichrome staining revealed significantly increased hypertrophy and fibrosis in PDH E1α-deficient hearts (P < .05 vs WT). Measurements of heart substrate metabolism in an ex vivo working heart perfusion system demonstrated a significant impairment of glucose oxidation in PDH E1α-deficient hearts during ischemia/reperfusion (P < .05 vs WT). Dichloroacetate, a PDH activator, increased glucose oxidation in WT hearts during ischemia/reperfusion and reduced myocardial infarct size in WT, but not in PDH E1α-deficient hearts. Immunoblotting results demonstrated that cardiac PDH E1α deficiency leads to an impaired ischemic AMP-activated protein kinase activation through Sestrin2-liver kinase B1 interaction which is responsible for an increased susceptibility of PDH E1α-deficient heart to ischemic insults. Thus, cardiac PDH E1α deficiency impairs ischemic AMP-activated protein kinase signaling and sensitizes hearts to the toxicological actions of ischemic stress.

No-Reflow Phoenomenon by Intracoronary Thrombus in Acute Myocardial Infarction

Recently, percutaneous coronary intervention has been the treatment of choice in most acute myocardial infarction cases. Although the results of percutaneous coronary interventions have ben good, the no-reflow phenomenon and distal embolization of intracoronary thrombus are still major problems even after successful interventions. In this article, we will briefly review the deleterious effects of no-reflow and distal embolization of intracoronary thrombus during percutaneous coronary interventions. The current trials focused on the prevention and treatment of the no-reflow phenomenon and intracoronary thrombus.

Effect of ranolazine on rat intrarenal arteries in vitro

Ranolazine is mainly used to treat patients with chronic stable angina in clinical practice. However, ranolazine does not lower significantly systemic blood pressure. The direct effect of ranolazine on vascular tone remains unknown. In the present study, we investigated the vascular effects and mechanisms of action of ranolazine in isolated rat intrarenal arteries. Rings of intrarenal arteries were mounted in a small vessel myography using two stainless steel wires for the measurement of isometric tension. L-type Ca²⁺ currents were recorded in isolated single renal arterial smooth muscle cells using patch clamp techniques in whole-cell mode. Ranolazine induced concentration-dependent relaxations in rings contracted with phenylephrine, but ranolazine failed to cause any relaxation in rings pre-contracted by U46619, 5-HT or endothelin-1. Ranolazine also induced relaxations in norepinephrine pre-contracted rings. Yohimbine failed to induce relaxation in rings pre-contracted by norepinephrine. Propranolol did not affect ranolazine-induced relaxation but the relaxant effect of ranolazine was much less than that of prazosin. Ranolazine-induced relaxations were slight but significantly attenuated by endothelial denudation. Partial inhibition was observed in endothelium-intact arteries exposed to a combination of iberiotoxin and apamin. Ranolazine at higher concentration (>30 μM) inhibited Ca²⁺-induced contraction in a noncompetitive manner. Ranolazine reduced L-type Ca²⁺ currents at potentials between -30 and 50 mV in isolated renal artery myocytes. Therefore it can be said that ranolazine has significant α₁-adrenergic receptor and weak calcium channel antagonistic effects in rat intrarenal arteries.

Psychological interventions for coronary heart disease

BACKGROUND

Psychological symptoms are strongly associated with coronary heart disease (CHD), and many psychological treatments are offered following cardiac events or procedures.

OBJECTIVES

Update the existing Cochrane review to (1) determine the independent effects of psychological interventions in patients with CHD (principal outcome measures included total or cardiac-related mortality, cardiac morbidity, depression, and anxiety) and (2) explore study-level predictors of the impact of these interventions.

SEARCH STRATEGY

The original review searched Cochrane Controleed Trials Register (CCTR, Issue 4, 2001), MEDLINE, EMBASE, PsycINFO, and CINAHL to December 2001. This was updated by searching the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE, PsycINFO and CINAHL from 2001 to January 2009. In addition, we searched reference lists of papers, and expert advice was sought for the original and update review.

SELECTION CRITERIA

Randomised controlled trials of psychological interventions compared to usual care, administered by trained staff. Only studies estimating the independent effect of the psychological component with a minimum follow-up of six months. Adults with specific diagnosis of CHD.

DATA COLLECTION AND ANALYSIS

Titles and abstracts of all references screened for eligibility by two reviewers independently; data extracted by the lead author and checked by a second reviewer. Authors contacted where possible to obtain missing information.

MAIN RESULTS

There was no strong evidence that psychological intervention reduced total deaths, risk of revascularisation, or non-fatal infarction. Amongst a smaller group of studies reporting cardiac mortality there was a modest positive effect of psychological intervention (relative risk: 0.80 (95% CI 0.64 to 1.00)). Furthermore, psychological intervention did result in small/moderate improvements in depression, standardised mean difference (SMD): -0.21 (95% CI -0.35, -0.08) and anxiety, SMD: -0.25 (95% CI -0.48 to -0.03). Results for mortality indicated some evidence of small-study bias, though results for other outcomes did not. Meta regression analyses revealed four significant predictors of intervention effects on depression were found: (1) an aim to treat type-A behaviours (ß = -0.32, p = 0.03) were more effective than other interventions. In contrast, interventions which (2) aimed to educate patients about cardiac risk factors (ß = 0.23, p = 0.03), (3) included client-led discussion and emotional support as core therapeutic components (ß = 0.31, p < 0.01), or (4) included family members in the treatment process (ß = 0.26, p < 0.01) were significantly less effective.

AUTHORS' CONCLUSIONS

Psychological treatments appear effective in treating psychological symptoms of CHD patients. Uncertainly remains regarding the subgroups of patients who would benefit most from treatment and the characteristics of successful interventions.

Class I/B antiarrhythmic property of ranolazine, a novel antianginal agent, in dog and human cardiac preparations

The aim of this study was to investigate the cellular electrophysiological effects of ranolazine on action potential characteristics. The experiments were carried out in dog and human cardiac preparations using the conventional microelectrode technique. In dog Purkinje fibres ranolazine produced a concentration- and frequency-dependent depression of the maximum rate of depolarization (V(max)) while action potential duration (APD) was shortened. In dog and human right ventricular papillary muscle ranolazine exerted no significant effect on APD, while it produced, like mexiletine, use-dependent depression of V(max) with relatively fast onset and offset kinetics. In dog midmyocardial preparations the drug did not exert statistically significant effect on repolarization at 10 μM, although a tendency toward prolongation was observed at 20 μM. A moderate lengthening of APD(90) by ranolazine was noticed in canine atrial preparations obtained from dogs in sinus rhythm and in tachypacing induced remodelled preparations. Use-dependent depression of V(max) was more pronounced in atria from dogs in sinus rhythm than those in remodelled atria or in the ventricle. These findings indicate that ranolazine, in addition to its known late sodium current blocking effect, also depresses peak I(Na) with class I/B antiarrhythmic characteristics. Although peak I(Na) inhibition by ranolazine is stronger in the atria, it is also substantial (at fast stimulation frequencies) in ventricular preparations. Ranolazine also decreased the dispersion of ventricular repolarization (the difference in APD(90) values between Purkinje fibres and papillary muscles), which can contribute to the antiarrhythmic property of the drug.

Molecular basis of ranolazine block of LQT-3 mutant sodium channels: evidence for site of action

1 We studied the effects of ranolazine, an antianginal agent with promise as an antiarrhythmic drug, on wild-type (WT) and long QT syndrome variant 3 (LQT-3) mutant Na(+) channels expressed in human embryonic kidney (HEK) 293 cells and knock-in mouse cardiomyocytes and used site-directed mutagenesis to probe the site of action of the drug. 2 We find preferential ranolazine block of sustained vs peak Na(+) channel current for LQT-3 mutant (DeltaKPQ and Y1795C) channels (IC(50)=15 vs 135 microM) with similar results obtained in HEK 293 cells and knock-in myocytes. 3 Ranolazine block of both peak and sustained Na(+) channel current is significantly reduced by mutation (F1760A) of a single residue previously shown to contribute critically to the binding site for local anesthetic (LA) molecules in the Na(+) channel. 4 Ranolazine significantly decreases action potential duration (APD) at 50 and 90% repolarization by 23+/-5 and 27+/-3%, respectively, in DeltaKPQ mouse ventricular myocytes but has little effect on APD of WT myocytes. 5 Computational modeling of human cardiac myocyte electrical activity that incorporates our voltage-clamp data predicts marked ranolazine-induced APD shortening in cells expressing LQT-3 mutant channels. 6 Our results demonstrate for the first time the utility of ranolazine as a blocker of sustained Na(+) channel activity induced by inherited mutations that cause human disease and further, that these effects are very likely due to interactions of ranolazine with the receptor site for LA molecules in the sodium channel.

The psychosocial versus material hypothesis to explain observed inequality in disability among older adults: data from the West of Scotland Twenty-07 Study

OBJECTIVES

The possible mechanisms for explaining health inequality are subject to debate. This study considers the roles of psychosocial and material mechanisms in observed inequalities in disability among older people.

DESIGN

Cross-sectional analysis of cohort study.

PARTICIPANTS

723 respondents aged 63 years from the West of Scotland Twenty-07 Study.

MAIN OUTCOME MEASURE

The Office of Population Census and Surveys Multidimensional Disability Severity Score. Respondents were dichotomised to the highest scoring tertile, and compared with the lowest and mid-tertiles combined.

EXPLANATORY MEASURES

Socioeconomic position across adulthood was measured in three ways. Respondents reported perceptions of their own financial position (perceived financial hardship) across four decades of adult life. Data on possession of several indicators of material wealth (eg, ownership of television and washing machine; material conditions) during the same periods were also ascertained. Standard occupational classification was also recorded, based on longest held occupation. The relationship between the measures of socioeconomic position and disability was examined using logistic regression, adjusting for sex, morbidity and lifestyle factors.

RESULTS

Perceived financial hardship and material conditions in earlier decades of life were found to be associated with reported disability. However, in the fully adjusted model, there was stronger evidence for material conditions as a predictor of disability: across four decades they remained an independent risk factor for disability after adjustment for sex, morbidity, lifestyle factors and perceived financial hardship. Those in the most deprived material conditions group had 2 1/2 times the odds of reporting severe disability than those in the reference group. After adjustment, evidence for an association between perceived financial hardship and reported disability was not convincing.

CONCLUSION

The data provide evidence to support the "material" explanation for observed inequalities in reported disability among older people.

Genetic variation in the endothelin system: do polymorphisms affect the therapeutic strategies?

Endothelin-1 (ET-1) exerts multiple biological effects, including vasoconstriction and the stimulation of cell proliferation in tissues both within and outside of the cardiovascular system. ET-1 is synthesized by ET-converting enzymes (ECE), chymases (CMAs), and non-ECE metalloproteases through a process regulated in an autocrine fashion in vascular and nonvascular cells. ET-1 acts through the activation of G(i)protein-coupled receptors. ET(A) receptors mediate vasoconstriction and cell proliferation, whereas ET(B) receptors are important for aldosterone secretion, endothelial cell (EC) migration, the release of nitric oxide (NO) and prostacyclin, the clearance of ET-1, and the inhibition of ECE-1. ET is activated in scleroderma, hypertension, atherosclerosis, restenosis, heart failure, idiopathic cardiomyopathy, and renal failure. Tissue concentrations more reliably reflect the activation of the ET system because of the predominantly abluminal secretion of the peptide. Experimental studies and clinical trials have demonstrated that ET-1 plays a major role in normal cardiovascular homeostasis and in the functional and structural changes observed in arterial and pulmonary hypertension, glomerulosclerosis, atherosclerosis, and heart failure. Accordingly, ET antagonists are promising new agents in the treatment of cardiovascular diseases. Single nucleotide polymorphisms (SNPs) of the genes of preproET-1, ECE-1, CMA, ET(A) and ET(B) receptors have been identified and can be important for their functional regulation. However, for most of them the association with disease conditions and the evidence for a functional role remain controversial. Thus, even though ET antagonists are being used for the treatment of pulmonary hypertension, there is no convincing evidence for a role of SNPs in affecting the therapeutic strategies.

Chronic activation of PPARα is detrimental to cardiac recovery after ischemia

High fatty acid oxidation (FAO) rates contribute to ischemia-reperfusion injury of the myocardium. Because peroxisome proliferator-activated receptor (PPAR)α regulates transcription of several FAO enzymes in the heart, we examined the response of mice with cardiac-restricted overexpression of PPARα (MHC-PPARα) or whole body PPARα deletion including the heart (PPARα−/−) to myocardial ischemia-reperfusion injury. Isolated working hearts from MHC-PPARα and nontransgenic (NTG) littermates were subjected to no-flow global ischemia followed by reperfusion. MHC-PPARα hearts had significantly higher FAO rates during aerobic and postischemic reperfusion (aerobic 1,479 ± 171 vs. 699 ± 117, reperfusion 1,062 ± 214 vs. 601 ± 70 nmol·g dry wt−1·min−1; P < 0.05) and significantly lower glucose oxidation rates compared with NTG hearts (aerobic 225 ± 36 vs. 1,563 ± 165, reperfusion 402 ± 54 vs. 1,758 ± 165 nmol·g dry wt−1·min−1; P < 0.05). In hearts from PPARα−/−mice, FAO was significantly lower during aerobic and reperfusion (aerobic 235 ± 36 vs. 442 ± 75, reperfusion 205 ± 25 vs. 346 ± 38 nmol·g dry wt−1·min−1; P < 0.05) whereas glucose oxidation was significantly higher compared with wild-type (WT) hearts (aerobic 2,491 ± 631 vs. 901 ± 119, reperfusion 2,690 ± 562 vs. 1,315 ± 172 nmol·g dry wt−1·min−1; P < 0.05). Increased FAO rates in MHC-PPARα hearts were associated with a markedly lower recovery of cardiac power (45 ± 9% vs. 71 ± 6% of preischemic levels in NTG hearts; P < 0.05). In contrast, the percent recovery of cardiac power of PPARα−/−hearts was not significantly different from that of WT hearts (80 ± 8% vs. 75 ± 9%). This study demonstrates that chronic activation of PPARα is detrimental to the cardiac recovery during reperfusion after ischemia.

Electrophysiological effects of azimilide in an in vitro model of simulated-ischemia and reperfusion in guinea-pig ventricular myocardium

There are few investigations on azimilide effects during ischemia/reperfusion. We have therefore investigated low concentrations of azimilide (0.1 and 0.5 micromol/l) versus Controls on action potential parameters and occurrence of repetitive responses during simulated ischemia and reperfusion. An in vitro model of "border zone" in guinea-pig ventricular myocardium (n=30) was used. Azimilide 0.5 micromol/l lengthened action potential duration in normoxic but not in ischemic-like conditions. Therefore an increased dispersion of action potential duration at 90% of repolarization during simulated ischemia in presence of azimilide was seen. Upon reperfusion, both normal and reperfused myocardium showed azimilide-induced action potential duration increase. There was a neutral effect on the occurrence of arrhythmias during simulated ischemia; however azimilide showed significant (P=0.033) antiarrhythmic properties following reperfusion. To mimic I(Kr) and I(Ks) blocking properties of azimilide we further used dofetilide 10 nmol/l with HMR 1556 1 nmol/l (N=9), which was accompanied by less severe shortening (P<0.05) of action potential duration at 90% of repolarization at 30 min of ischemic-like conditions (-43+/-9%), as compared with azimilide 0.5 micromol/l (-64+/-5%) but similar to what seen with azimilide 0.1 micromol/l (-53+/-5%) and Controls (-52+/-6%). During reperfusion, 2/9 (22%) preparations had sustained activities, which was less than what observed in Controls (5/10, 50%) and with azimilide 0.5 micromol/l (0/10, 0%), although not statistically different (respectively, P=0.35 and P=0.21). Lack versus homogenous class III effects of azimilide in respectively simulated ischemia and reperfusion may explain its different efficacy on arrhythmias, although prevention of reperfusion arrhythmias calls for other than just its I(Kr) and I(Ks) blocking properties.

Electrophysiologic properties and antiarrhythmic actions of a novel antianginal agent

Ranolazine is a novel antianginal agent capable of producing anti-ischemic effects at plasma concentrations of 2 to 6 microM without a significant reduction of heart rate or blood pressure. This review summarizes the electrophysiologic properties of ranolazine. Ranolazine significantly blocks I(Kr) (IC(50) = 12 microM), late I(Na), late I(Ca), peak I(Ca), I(Na-Ca) (IC(50) = 5.9, 50, 296, and 91 microM, respectively) and I(Ks) (17% at 30 microM), but causes little or no inhibition of I(to) or I(K1). In left ventricular tissue and wedge preparations, ranolazine produces a concentration-dependent prolongation of action potential duration (APD) in epicardium, but abbreviation of APD of M cells, leading to either no change or a reduction in transmural dispersion of repolarization (TDR). The result is a modest prolongation of the QT interval. Prolongation of APD and QT by ranolazine is fundamentally different from that of other drugs that block I(Kr) and induce torsade de pointes in that APD prolongation is rate-independent (ie, does not display reverse rate-dependent prolongation of APD) and is not associated with early after depolarizations, triggered activity, increased spatial dispersion of repolarization, or polymorphic ventricular tachycardia. Torsade de pointes arrhythmias were not observed spontaneously nor could they be induced with programmed electrical stimulation in the presence of ranolazine at concentrations as high as 100 microM. Indeed, ranolazine was found to possess significant antiarrhythmic activity, acting to suppress the arrhythmogenic effects of other QT-prolonging drugs. Ranolazine produces ion channel effects similar to those observed after chronic exposure to amiodarone (reduced late I(Na), I(Kr), I(Ks), and I(Ca)). Ranolazine's actions to reduce TDR and suppress early after depolarization suggest that in addition to its anti-anginal actions, the drug possesses antiarrhythmic activity.

Ischemic heart disease: metabolic approaches to management

The number of patients with coronary artery disease and its risk factors is increasing in Western nations. New treatments for these patients may soon include a class of agents known as the metabolic modulators. This group of agents consists of the partial fatty acid oxidation inhibitors trimetazidine and ranolazine, as well as dichloroacetate, which promotes carbohydrate utilization. Metabolic modulators also include the nutriceuticals L-carnitine and D-ribose. The available evidence regarding the benefits of each of these five agents is reviewed.

Risk factors, confounding, and the illusion of statistical control

When experimental designs are premature, impractical, or impossible, researchers must rely on statistical methods to adjust for potentially confounding effects. Such procedures, however, are quite fallible. We examine several errors that often follow the use of statistical adjustment. The first is inferring a factor is causal because it predicts an outcome even after "statistical control" for other factors. This inference is fallacious when (as usual) such control involves removing the linear contribution of imperfectly measured variables, or when some confounders remain unmeasured. The converse fallacy is inferring a factor is not causally important because its association with the outcome is attenuated or eliminated by the inclusion of covariates in the adjustment process. This attenuation may only reflect that the covariates treated as confounders are actually mediators (intermediates) and critical to the causal chain from the study factor to the study outcome. Other problems arise due to mismeasurement of the study factor or outcome, or because these study variables are only proxies for underlying constructs. Statistical adjustment serves a useful function, but it cannot transform observational studies into natural experiments, and involves far more subjective judgment than many users realize.

Electrophysiological effects of ranolazine, a novel antianginal agent with antiarrhythmic properties

BACKGROUND

Ranolazine is a novel antianginal agent capable of producing antiischemic effects at plasma concentrations of 2 to 6 micromol/L without reducing heart rate or blood pressure. The present study examines its electrophysiological effects in isolated canine ventricular myocytes, tissues, and arterially perfused left ventricular wedge preparations.

METHODS AND RESULTS

Transmembrane action potentials (APs) from epicardial and midmyocardial (M) regions and a pseudo-ECG were recorded simultaneously from wedge preparations. APs were also recorded from epicardial and M tissues. Whole-cell currents were recorded from epicardial and M myocytes. Ranolazine inhibited I(Kr) (IC50=11.5 micromol/L), late I(Na), late I(Ca), peak I(Ca), and I(Na-Ca) (IC50=5.9, 50, 296, and 91 micromol/L, respectively) and I(Ks) (17% at 30 micromol/L), but caused little or no inhibition of I(to) or I(K1). In tissues and wedge preparations, ranolazine produced a concentration-dependent prolongation of AP duration of epicardial but abbreviation of that of M cells, leading to reduction or no change in transmural dispersion of repolarization (TDR). At [K+]o=4 mmol/L, 10 micromol/L ranolazine prolonged QT interval by 20 ms but did not increase TDR. Extrasystolic activity and spontaneous torsade de pointes (TdP) were never observed, and stimulation-induced TdP could not be induced at any concentration of ranolazine, either in normal or low [K+]o. Ranolazine (5 to 20 micromol/L) suppressed early afterdepolarizations (EADs) and reduced the increase in TDR induced by the selective I(Kr) blocker d-sotalol.

CONCLUSIONS

Ranolazine produces ion channel effects similar to those observed after chronic amiodarone (reduced I(Kr), I(Ks), late I(Na), and I(Ca)). The actions of ranolazine to suppress EADs and reduce TDR suggest that, in addition to its antianginal actions, the drug may possess antiarrhythmic activity.

Ranolazine: ion-channel-blocking actions and in vivo electrophysiological effects

Ranolazine is a novel anti-ischemic drug that prolongs the QT interval. To evaluate the potential mechanisms and consequences, we studied: (i) Ranolazine's effects on HERG and IsK currents in Xenopus oocytes with two-electrode voltage clamp; (ii) effects of ranolazine, compared to d-sotalol, on effective refractory period (ERP), QT interval and ventricular rhythm in a dog model of acquired long QT syndrome; and (iii) effects on selected native currents in canine atrial myocytes with whole-cell patch-clamp technique. Ranolazine inhibited HERG and IsK currents with different potencies. HERG was inhibited with an IC(50) of 106 micromol l(-1), whereas the IC(50) for IsK was 1.7 mmol l(-1). d-Sotalol caused reverse use-dependent ERP and QT interval prolongation, whereas ranolazine produced modest, nonsignificant increases that plateaued at submaximal doses. Neither drug affected QRS duration. d-Sotalol had clear proarrhythmic effects, with all d-sotalol-treated dogs developing torsades de pointes (TdP) ventricular tachyarrhythmias, of which they ultimately died. In contrast, ranolazine did not generate TdP. Effects on I(Kr) and I(Ks) were similar to those on HERG and IsK. Ranolazine blocked I(Ca) with an IC(50) of approximately 300 micromol l(-1). I(Na) was unaffected. We conclude that ranolazine inhibits I(Kr) by blocking HERG currents, inhibits I(Ca) at slightly larger concentrations, and has modest and self-limited effects on the QT interval. Unlike d-sotalol, ranolazine does not cause TdP in a dog model. The greater safety of ranolazine may be due to its ability to inhibit I(Ca) at concentrations only slightly larger than those that inhibit I(Kr), thus producing offsetting effects on repolarization.

Antiarrhythmic effects of ranolazine in a guinea pig in vitro model of long-QT syndrome

Prolongation of the QT interval of the ECG is associated with increased risk of torsades de pointes ventricular tachycardia. Ranolazine, a novel antianginal agent, is reported to decrease the delayed rectifier potassium current, I(Kr), and to increase action potential duration (APD) and the QT interval. However, ranolazine is also reported to reduce late sodium current (late I(Na)), a depolarizing current that contributes to prolongation of the plateau of the ventricular action potential. We hypothesized that ranolazine would decrease APD and the occurrence of arrhythmias when late I(Na) is increased. Therefore, we measured the effects of ranolazine alone and in the presence of anemone toxin (ATX)-II, whose action mimics the sodium channelopathy associated with long-QT3 syndrome, on epicardial monophasic action potentials and ECGs recorded from guinea pig isolated hearts. Ranolazine (0.1-50 microM) prolonged monophasic APD at 90% repolarization (MAPD(90)) by up to 22% but did not cause either early afterdepolarizations (EADs) or ventricular tachycardia (VT). ATX-II (1-20 nM) markedly increased APD and caused EADs and VT. Ranolazine (5-30 microM) significantly attenuated increases in MAPD(90) and reduced episodes of EADs and VT produced by ATX-II. Ranolazine also attenuated the synergistic effect of MAPD(90) increase caused by combinations of ATX-II and blockers of I(K) [E-4031; 1-[2-(6-methyl-2-pyridyl)ethyl]-4-methylsulfonylaminobenzoyl)piperidine]. Thus, although ranolazine alone prolonged APD, it reduced APD and ventricular arrhythmias caused by agents that increased late I(Na) and decreased I(K).

Coronary heart disease: the female heart is vulnerable

During the past decade, an overall theme has emerged, validating the exploration of gender-based differences in coronary heart disease (CHD) as a basis for clinical strategies to improve outcomes for women. Underrepresentation of women in most of CHD and lack of gender-specific reporting in many clinical trials continue to limit the available knowledge and evidence-based medicine needed to devise optimal managements for women with CHD. Control of conventional coronary risk factors provides comparable cardioprotection for men and women. Current evidence fails to show cardiac protection from menopausal hormone therapy. Clinical presentations of coronary heart disease (CHD) and management strategies differ between the sexes. Underutilization of proven beneficial therapies is a contributor to less-favorable outcomes in women. The contemporary increased application of appropriate diagnostic, therapeutic, and interventional managements has favorably altered the prognosis for women, particularly when the data are adjusted for baseline characteristics. Better education of women during office visits, earlier and more aggressive control of coronary risk factors, and a greater index of suspicion regarding chest pain and its appropriate evaluation may help to reverse the trend of late referral and late intervention. Research indicates that behavioral changes on the part of women and reshaping of practice patterns by their health care providers may dramatically reduce the number of women disabled and killed by CHD each year.

Comparing symptoms of depression and anxiety as predictors of cardiac events and increased health care consumption after myocardial infarction

OBJECTIVES

We sought to compare symptoms of depression and anxiety as predictors of incomplete recovery after a first myocardial infarction (MI).

BACKGROUND

Depressive symptoms have been related to post-MI mortality and health care consumption, but little is known about the effect of anxiety. We wanted to examine the effect of emotional distress on health care consumption and whether depressive symptomatology is a better predictor of prognosis than anxiety.

METHODS

Subjects were 318 men (mean age 58 years) who completed the depression, anxiety, and hostility scales from the 90-item symptom check list after they survived a first MI.

RESULTS

After an average follow-up of 3.4 years, there were 25 cardiac events (fatal or non-fatal MI). Symptoms of both depression (hazard ratio [HR] 2.32, 95% confidence interval [CI] 1.04 to 5.18; p = 0.039) and anxiety (HR 3.01, 95% CI 1.20 to 7.60; p = 0.019) were associated with cardiac events, adjusting for age, left ventricular ejection fraction, and use of antidepressants. However, a multivariate analysis including all three negative emotions indicated that symptoms of anxiety (HR 2.79, 95% CI 1.11 to 7.03; p = 0.029) explained away the relationship between depressive symptoms and cardiac events. Regarding health care consumption, anxiety (OR 2.00, 95% CI 1.24 to 3.22; p = 0.005), but not depression/hostility, was a predictor of cardiac rehospitalization and frequent visits at the cardiac outpatient clinic.

CONCLUSIONS

Symptoms of depression and anxiety were associated with cardiac events. Anxiety was an independent predictor of both cardiac events and increased health care consumption and accounted for the relationship between depressive symptoms and prognosis. Symptoms of anxiety need to be considered in the risk stratification and treatment of post-MI patients.

Psychological interventions for coronary heart disease

BACKGROUND

Psychological interventions can form part of comprehensive cardiac rehabilitation programmes (CCR). These interventions may include stress management interventions, which aim to reduce stress, either as an end in itself or to reduce risk for further cardiac events in patients with heart disease.

OBJECTIVES

To determine the effectiveness of psychological interventions, in particular stress management interventions, on mortality and morbidity, psychological measures, quality of life, and modifiable cardiac risk factors, in patients with coronary heart disease (CHD).

SEARCH STRATEGY

We searched CCTR to December 2001 (Issue 4, 2001), MEDLINE 1999 to December 2001 and EMBASE 1998 to the end of 2001, PsychINFO and CINAHL to December 2001. In addition, searches of reference lists of papers were made and expert advice was sought.

SELECTION CRITERIA

RCTs of non-pharmacological psychological interventions, administered by trained staff, either single modality interventions or a part of CCR with minimum follow up of 6 months. Adults of all ages with CHD (prior myocardial infarction, coronary artery bypass graft or percutaneous transluminal coronary angioplasty, angina pectoris or coronary artery disease defined by angiography). Stress management (SM) trials were identified and reported in combination with other psychological interventions and separately.

DATA COLLECTION AND ANALYSIS

Studies were selected, and data were abstracted, independently by two reviewers. Authors were contacted where possible to obtain missing information.

MAIN RESULTS

Thirty six trials with 12,841 patients were included. Of these, 18 (5242 patients) were SM trials. Quality of many trials was poor with the majority not reporting adequate concealment of allocation, and only 6 blinded outcome assessors. Combining the results of all trials showed no strong evidence of effect on total or cardiac mortality, or revascularisation. There was a reduction in the number of non-fatal reinfarctions in the intervention group (OR 0.78 (0.67, 0.90), but the two largest trials (with 4809 patients randomized) were null for this outcome, and there was statistical evidence of publication bias. Similar results were seen for the SM subgroup of trials. Provision of any psychological intervention or SM intervention caused small reductions in anxiety and depression. Few trials reported modifiable cardiac risk factors or quality of life.

REVIEWERS' CONCLUSIONS

Overall psychological interventions showed no evidence of effect on total or cardiac mortality, but did show small reductions in anxiety and depression in patients with CHD. Similar results were seen for SM interventions when considered separately. However, the poor quality of trials, considerable heterogeneity observed between trials and evidence of significant publication bias make the pooled finding of a reduction in non-fatal myocardial infarction insecure.

Effect of Combined Intracoronary Adenosine and Nicorandil on No-Reflow Phenomenon During Percutaneous Coronary Intervention

BACKGROUND

This study aimed to clarify the effect of intracoronary administration of combined adenosine and nicorandil on the no-reflow phenomenon.

METHODS AND RESULTS

Fifty patients (67+/-10 years, 30 male) with acute myocardial infarction (AMI) who developed no-reflow phenomenon during primary percutaneous coronary intervention (PCI) between June 2001 and May 2003 comprised the study group, which was divided into 2 groups: group I [25 patients, 67+/-10 years, 13 male; adenosine (24 microg/ml) alone in addition to nitrate] and group II [25 patients, 66+/-9 years, 17 male; combined intracoronary administration of adenosine and nicorandil (2 mg/ml) in addition to nitrate]. In-hospital and 6-month major adverse cardiac events (MACE) after PCI were compared between the 2 groups. Risk factors of coronary disease, left ventricular ejection fraction and wall motion score were not significantly different between the 2 groups (p=NS). Time interval from the onset of chest pain to PCI, number of involved vessels, lesion type according to ACC/AHA classification and TIMI flow grade (TFG) were not significantly different in both groups (p=NS). Incidence of thrombosis or dissection after balloon angioplasty, diameter and length of stent, and use of Reopro during PCI were not significantly different. TFG after PCI (2.0+/-0.9 vs 2.6+/-0.6, p=0.024), DeltaTFG (1.5+/-1.1 vs 2.2+/-1.0, p=0.033) and difference in TIMI frame count (TFC) before and after PCI (DeltaTFC) were greater in group II than group I (45.2+/-24.5 vs 63.6+/-23.2, p=0.014). Myocardial blush score 3 was obtained more frequently in group II than group I (44% vs 76%, p=0.014). In-hospital death did not occur in any of group II, but 4 patients of group I died (p=0.043). Two cases of MACE developed in each group and heart failure occurred in 3 (12%) of group I and 1 (4%) of group II patients during the 6-month follow-up (p=NS).

CONCLUSIONS

Intracoronary administration of adenosine combined with nicorandil may improve both the occurrence of no-reflow in patients during PCI for AMI and short-term clinical outcome, compared with adenosine alone.

Psychosocial factors and their association with clinical outcomes in patients with heart failure: why clinicians do not seem to care

Poor quality of life, social isolation, depression and anxiety all have been linked to increased risk of rehospitalization and mortality in patients with heart failure. Yet, despite evidence of their importance to outcomes in heart failure patients, psychosocial factors are assessed and treated infrequently in clinical practice. Potential reasons for this include: (1) inadequate dissemination of research about the link between psychosocial factors and outcomes; (2) insufficient training in heart-mind interactions that precludes clinicians from taking advantage of what is known; (3) perceived problems with interventions or with the science of heart-mind interactions that interfere with acceptance of what is known; (4) concerns about how to measure psychosocial factors in clinical practice; and (5) lack of curiosity from clinicians about the role of psychosocial factors in their patients. In this article, each of these possible explanations is explored and recommendations suggested.

Psychosocial factors and public health: a suitable case for treatment?

Adverse psychosocial exposure or "misery" is associated with physical disease. This association may not be causal. Rather it may reflect issues of reverse causation, reporting bias, and confounding by aspects of the material environment typically associated with misery. A non-causal relation will not form the basis of effective public health interventions. This may be why psychosocial interventions have, so far, showed little effect on objective physical health outcomes. This paper reviews evidence for the "psychosocial hypothesis" and suggests strategies for clarifying these issues. It concludes that, although misery is clearly a bad thing as it erodes people's quality of life, there is little evidence that psychosocial factors cause physical disease. In the absence of better evidence, suggestions that psychosocial interventions are needed to improve population physical health, in both absolute and relative terms, seem premature.

Are psychosocial factors associated with the pathogenesis and consequences of cardiovascular disease in the elderly?

It is well known that older individuals are at higher risk of developing cardiovascular disease (CVD). In addition, evidence exists for the relationship between psychosocial factors and the pathogenesis and cognitive consequences of CVD. However, less is known about the effect of psychosocial factors on the development and consequences of CVD in older individuals. Using a biopsychosocial framework, this article examines the influence of psychosocial factors, specifically depression, anxiety, and social isolation on older persons with CVD as well as the influence of CVD on psychosocial factors. The effectiveness of interventions for modifying adverse psychosocial factors is also discussed.

AMP-activated protein kinase (AMPK) control of fatty acid and glucose metabolism in the ischemic heart

Myocardial ischemia is the leading cause of all cardiovascular deaths in North America. Myocardial ischemia is accompanied by profound changes in metabolism including alterations in glucose and fatty acid metabolism, increased uncoupling of glucose oxidation from glycolysis and accumulation of protons within the myocardium. These changes can contribute to a poor functional recovery of the heart. One key player in the ischemia-induced alteration in fatty acid and glucose metabolism is 5'AMP-activated protein kinase (AMPK). Accumulating evidence suggest that activation of AMPK during myocardial ischemia both increases glucose uptake and glycolysis while also increasing fatty acid oxidation during reperfusion. Gain-of-function mutations of AMPK in cardiac muscle may also be causally related to the development of hypertrophic cardiomyopathies. Therefore, a better understanding of role of AMPK in cardiac metabolism is necessary to appropriately modulate its activity as a potential therapeutic target in treating ischemia reperfusion injuries. This review attempts to update some of the recent findings that delineate various pathways through which AMPK regulates glucose and fatty acid metabolism in the ischemic myocardium.

Clinical trials update from the American Heart Association meeting: PROSPER, DIAL, home care monitoring trials, immune modulation therapy, COMPANION and anaemia in heart failure

This article continues a series of reports on research developments of particular interest to those involved in the management of patients with heart failure. Summaries of the following trials, reported at the 75th Scientific Sessions of the American Heart Association held in Chicago, Illinois between 17th and 20th November 2002 are included: PROSPER; DIAL; home care monitoring trials; immune modulation therapy; COMPANION; and anaemia in heart failure.

In-hospital symptoms of depression do not predict mortality 3 years after myocardial infarction

BACKGROUND

The main aim of this study was to examine the relationship between symptoms of depression following myocardial infarction (MI) and 3-year survival status.

METHODS

The Beck Depression Inventory was completed by 288 patients hospitalized for MI. Patients' cardiological status, including indices of disease severity, were recorded or derived from hospital notes. Three-year survival status was determined using patient information systems and cause of death ascertained from death certificates.

RESULTS

During the 3 years of follow-up, 38 patients (13%) died, 33 (11%) from cardiac causes. Symptoms of depression did not predict either cardiac-specific or all-cause mortality. Similarly, in-hospital levels of anxiety were not associated with prognosis. In contrast, measures of disease severity and discharge medication status were strong prognostic indicators. Depression was not related to measures of disease severity at entry to the study.

CONCLUSIONS

Symptoms of depression following MI do not predict longer-term survival, although measures of disease severity and discharge medication status do. Previous positive results for depression and cardiac mortality in MI patients could reflect the occasional confounding of depression with disease severity.

Depression as a risk factor for non-suicide mortality in the elderly

Depression can be a consequence of medical illness and disability, yet recent literature suggests it may also influence morbidity and mortality through a variety of behavioral and biological mediators. Relatively little is known about the complex temporal relations among behavior, affect, motivation, and pathophysiology to account for the association between depression and mortality. We performed a systematic review of the recent literature (1997-2001) examining the evidence linking depression to non-suicide mortality, describe possible mediators of the depression mortality effect, and identify important next steps in this area of research, including: a) the development of well-specified a-priory mediator models that articulate how depression leads to mortality; b) the conduct of longitudinal studies in which depression and behavioral and pathophyisological mediators are assessed simultaneously; c) treatment studies for depression that include assessments of associated changes in health-related quality of life, medical morbidity, and mortality; and d) treatment studies for behavioral risk factors and medical conditions that include assessment of depressive symptoms.

B-type natriuretic peptide predicts sudden death in patients with chronic heart failure

BACKGROUND

Given the high incidence of sudden death in patients with chronic heart failure (CHF) and the efficacy of implantable cardioverter-defibrillators, an appropriate tool for the prediction of sudden death is desirable. B-type natriuretic peptide (BNP) has prognostic significance in CHF, and the stimuli for its production cause electrophysiological abnormalities. This study tests BNP levels as a predictor of sudden death.

METHODS AND RESULTS

BNP levels, in addition to other neurohormonal, clinical, and hemodynamic variables, were obtained from 452 patients with a left ventricular ejection fraction (LVEF) < or =35%. For prediction of sudden death, only survivors without heart transplantation (HTx) or a mechanical assist device and patients who died suddenly were analyzed. Up to 3 years, 293 patients survived without HTx or a mechanical assist device, 89 patients died, and 65 patients underwent HTx. Mode of death was sudden in 44 patients (49%), whereas 31 patients (35%) had pump failure and 14 patients (16%) died from other causes. Univariate risk factors of sudden death were log BNP (P=0.0006), log N-terminal atrial natriuretic peptide (P=0.003), LVEF (P=0.005), log N-terminal BNP (P=0.006), systolic blood pressure (P=0.01), big endothelin (P=0.03), and NYHA class (P=0.04). In the multivariate model, log BNP level was the only independent predictor of sudden death (P=0.0006). Using a cutoff point of log BNP <2.11 (130 pg/mL), Kaplan-Meier sudden death-free survival rates were significantly higher in patients below (99%) compared with patients above (81%) this cutoff point (P=0.0001).

CONCLUSION

BNP levels are a strong, independent predictor of sudden death in patients with CHF.

Statins and chronic heart failure: do we need a large-scale outcome trial?

Hydroxymethylglutaryl-coenzyme A reductase inhibitors (statins) are of proven clinical benefit in coronary heart disease, at least in those patients who do not have overt chronic heart failure (CHF). However, as there have been no prospective clinical trials of statins in CHF patients, the question arises as to whether the benefits observed in the absence of CHF can be necessarily inferred in those patients in whom CHF is established. In this review, the evidence base stating support of the use of statins in CHF is presented, as well as theoretical considerations as to why these agents may not necessarily be of benefit in this setting. The beneficial potential of statins clearly relates to their plaque stabilization properties and associated improvements in endothelial function, which together should reduce the risk of further infarction and, perhaps, the ischemic burden on the failing ventricle. Furthermore, these agents may have beneficial effects independent of lipid lowering. These include actions on neoangiogenesis, downregulation of AT(1) receptors, inhibition of proinflammatory cytokine activity and favorable modulation of the autonomic nervous system. The potential adverse effects of statins in CHF include reduction in levels of coenzyme Q10 (which may further exacerbate oxidative stress in CHF) and loss of the protection that lipoproteins may provide through binding and detoxifying endotoxins entering the circulation via the gut. In support of these possibilities are epidemiologic data linking a lower serum cholesterol with a poorer prognosis in CHF. These uncertainties indicate the need for a definitive outcome trial to assess the efficacy and safety of statins in CHF, despite their current widespread, non-evidence based use in this population.