Cardiac Calcitropes, Myotropes, and Mitotropes: JACC Review Topic of the Week.

The term "inotrope" is familiar and intimately connected with pharmaceuticals clinically used for treatment of low cardiac output with cardiogenic shock. Traditional inotropic agents exert their effect by modulating calcium signaling in the myocardium. Their use is associated with poor long-term outcomes. Newer molecules in development intend to break from calcium mediation and the associated detrimental long-term effects by targeting distinct mechanisms of action to improve cardiac performance. Thus, "inotropy" does not sufficiently describe the range of potential novel pharmaceutical products. To enhance communication around and evaluation of current, emerging, and potential therapies, this review proposes a novel nuanced and holistic framework to categorize pharmacological agents that improve myocardial performance based on 3 myocardial mechanisms: calcitropes, which alter intracellular calcium concentrations; myotropes, which affect the molecular motor and scaffolding; and mitotropes, which influence energetics. Novel chemical entities can easily be incorporated into this structure, distinguishing themselves based on their mechanisms and clinical outcomes

Why has positive inotropy failed in chronic heart failure? Lessons from prior inotrope trials.

Current pharmacological therapies for heart failure with reduced ejection fraction are largely either repurposed anti-hypertensives that blunt overactivation of the neurohormonal system or diuretics that decrease congestion. However, they do not address the symptoms of heart failure that result from reductions in cardiac output and reserve. Over the last few decades, numerous attempts have been made to develop and test positive cardiac inotropes that improve cardiac haemodynamics. However, definitive clinical trials have failed to show a survival benefit. As a result, no positive inotrope is currently approved for long-term use in heart failure. The focus of this state-of-the-art review is to revisit prior clinical trials and to understand the causes for their findings. Using the learnings from those experiences, we propose a framework for future trials of such agents that maximizes their potential for success. This includes enriching the trials with patients who are most likely to derive benefit, using biomarkers and imaging in trial design and execution, evaluating efficacy based on a wider range of intermediate phenotypes, and collecting detailed data on functional status and quality of life. With a rapidly growing population of patients with advanced heart failure, the epidemiologic insignificance of heart transplantation as a therapeutic intervention, and both the cost and morbidity associated with ventricular assist devices, there is an enormous potential for positive inotropic therapies to impact the outcomes that matter most to patients

Vasodilators in the treatment of acute heart failure: what we know, what we don’t

Although we have recently witnessed substantial progress in management and outcome of patients with chronic heart failure, acute heart failure (AHF) management and outcome have not changed over almost a generation. Vasodilators are one of the cornerstones of AHF management; however, to a large extent, none of those currently used has been examined by large, placebo-controlled, non-hemodynamic monitored, prospective randomized studies powered to assess the effects on outcomes, in addition to symptoms. In this article, we will discuss the role of vasodilators in AHF trying to point out which are the potentially best indications to their administration and which are the pitfalls which may be associated with their use. Unfortunately, most of this discussion is only partially evidence based due to lack of appropriate clinical trials. In general, we believe that vasodilators should be administered early to AHF patients with normal or high blood pressure (BP) at presentation. They should not be administered to patients with low BP since they may cause hypotension and hypoperfusion of vital organs, leading to renal and/or myocardial damage which may further worsen patients’ outcome. It is not clear whether vasodilators have a role in either patients with borderline BP at presentation (i.e., low-normal) or beyond the first 1–2 days from presentation. Given the limitations of the currently available clinical trial data, we cannot recommend any specific agent as first line therapy, although nitrates in different formulations are still the most widely used in clinical practice

A novel approach to improve cardiac performance: cardiac myosin activators

Decreased systolic function is a central factor in the pathogenesis of heart failure, yet there are no safe medical therapies to improve cardiac function in patients. Currently available inotropes, such as dobutamine and milrinone, increase cardiac contractility at the expense of increased intracellular concentrations of calcium and cAMP, contributing to increased heart rate, hypotension, arrhythmias, and mortality. These adverse effects are inextricably linked to their inotropic mechanism of action. A new class of pharmacologic agents, cardiac myosin activators, directly targets the kinetics of the myosin head. In vitro studies have demonstrated that these agents increase the rate of effective myosin cross-bridge formation, increasing the duration and amount of myocyte contraction, and inhibit non-productive consumption of ATP, potentially improving myocyte energy utilization, with no effect on intracellular calcium or cAMP. Animal models have shown that this novel mechanism increases the systolic ejection time, resulting in improved stroke volume, fractional shortening, and hemodynamics with no effect on myocardial oxygen demand, culminating in significant increases in cardiac efficiency. A first-in-human study in healthy volunteers with the lead cardiac myosin activator, CK-1827452, as well as preliminary results from a study in patients with stable chronic heart failure, have extended these findings to humans, demonstrating significant increases in systolic ejection time, fractional shortening, stroke volume, and cardiac output. These studies suggest that cardiac myosin activators offer the promise of a safe and effective treatment for heart failure. A program of clinical studies are being planned to test whether CK-1827452 will fulfill that promise

Significant evidence for a heritable contribution to cancer predisposition: a review of cancer familiality by site

<p>Abstract</p> <p>Background/Aims</p> <p>Sound and rigorous well-established, and newly extended, methods for genetic epidemiological analysis were used to analyze population evidence for genetic contributions to risk for numerous common cancer sites in Utah. The Utah Population Database (UPDB) has provided important illumination of the familial contribution to cancer risk by cancer site.</p> <p>Methods</p> <p>With over 15 years of new cancer data since the previous comprehensive familial cancer analysis, we tested for excess familial clustering using an expanded Genealogical Index of Familiality (dGIF) methodology that provides for a more informative, but conservative test for the existence of a genetic contribution to familial relatedness in cancer.</p> <p>Results</p> <p>Some new cancer sites have been analyzed for the first time, having achieved sufficiently large sample size with additions to the UPDB. This new analysis has identified 6 cancer sites with significant evidence for a heritable contribution to risk, including lip, chronic lymphocytic leukemia, thyroid, lung, prostate, and melanoma.</p> <p>Conclusions</p> <p>Both environmentally and genetically-based familial clustering have clinical significance, and these results support increased surveillance for cancer of the same sites among close relatives of affected individuals for many more cancers than are typically considered.</p

Early dyspnoea relief in acute heart failure: prevalence, association with mortality, and effect of rolofylline in the PROTECT Study

AIMS: Dyspnoea and pulmonary and/or peripheral congestion are the most frequent manifestations of acute heart failure (AHF) and are important targets for therapy. We have assessed changes in dyspnoea, their relationship with mortality, and the effects of the adenosine A1 receptor antagonist rolofylline on these endpoints in patients enrolled in the PROTECT trial. METHODS AND RESULTS: PROTECT was a prospective, double-blind, placebo-controlled study assessing the effect of rolofylline in patients hospitalized for AHF with dyspnoea, fluid overload, increased plasma natriuretic peptides, and mild-to-moderate renal dysfunction. Early dyspnoea relief, prospectively defined as moderately or markedly better dyspnoea at both 24 and 48 h after the start of study drug administration, occurred in 49.8% of the patients. Early dyspnoea relief was associated with greater weight loss and with reduced mortality at Days 14 and 30 [hazard ratio (HR) 0.28, 95% confidence interval (CI): 0.15, 0.50; and 0.35, 95% CI: 0.22, 0.55, respectively]. Rolofylline administration was associated with an increase in the proportion of patients showing early dyspnoea relief (HR 1.30; 95% CI: 1.08, 1.57) and with a numerically lower mortality at 14 and 30 days, largely driven by the mortality due to HF [at 30 days, HR (95% CI, P-value): 0.65 (0.38-1.10, P= 0.107)]. Rolofylline did not reduce episodes of in-hospital worsening HF or post-discharge re-admissions, nor did it improve survival at 60 or 180 days. CONCLUSION: The present analysis from PROTECT demonstrated that more weight loss was associated with early dyspnoea relief and reduced short-term mortality

Hotline sessions presented at the American College of Cardiology Congress 2009

The article summarizes the results of clinical trials in the field of cardiovascular medicine, which were presented during the Hotline Sessions at the annual meeting of the American College of Cardiology in Orlando, USA, from 28th March to 31st March 2009. The data were presented by leading experts in the field with relevant positions within the trials. Unpublished reports should be considered as preliminary data as the analysis may change in the final publications. The summaries presented in the manuscript were generated from the oral presentations and provide the readers with the comprehensive information on the results of the latest clinical trials in cardiovascular medicine

Permutation criteria to evaluate multiple clinical endpoints in a proof-of-concept study: lessons from Pre-RELAX-AHF

Clinically relevant endpoints cannot be routinely targeted with reasonable power in a small study. Hence, proof-of-concept studies are often powered to a primary surrogate endpoint. However, in acute heart failure (AHF) effects on surrogates have not translated into clinical benefit in confirmatory studies. Although observing an effect on one of many endpoints due to chance is likely, observing concurrent positive trends across several outcomes by chance is usually unlikely. Pre-RELAX-AHF, which compared 4 relaxin doses with placebo in AHF, has shown favourable trends versus placebo (one-sided P <0.10) on six of nine clinical endpoints in the 30 mu g/kg/day group. To illustrate evaluation of multiple, correlated clinical endpoints for evidence of efficacy and for dose selection, a permutation method was applied retrospectively. By randomly re-assigning the treatment group to the actual data for each of the 229 subjects, 20,000 permutation samples were constructed. The permutation P value for at least six favourable trends among nine endpoints in any dose groups was 0.0073 (99.9% CI 0.0053-0.0093). This is higher than would be expected if the endpoints were uncorrelated (0.00026), but much lower than the probability of observing one of nine comparisons significant at the traditional two-sided P <0.05 (0.74). Thus, the result was unlikely due to correlated endpoints or to chance. Examining consistency of effect across multiple clinical endpoints in a proof-of-concept study may identify efficacious therapies and enable dose selection for confirmatory trials. The merit of the approach described requires confirmation through prospective application in designing future studies

Left ventricle remodelling by double-patch sandwich technique

BACKGROUND: The sandwich double-patch technique was adopted as an alternative method for reconstruction of the left ventricle after excision of postinfarction dysfunctional myocardium to solve technical problems due to the thick edges of the ventricular wall. METHODS: Over a 5-year period, 12 of 21 patients with postinfarction antero-apical left ventricular aneurysm had thick wall edges after wall excision. It was due to akinetic muscular thick tissue in 6 cases, while in the other 6 with classic fibrous aneurysm, thick edges remained after the cut of the border zone. The ventricular opening was sandwiched between two patches and this is a technique which is currently used for the treatment of the interventricular septum rupture. In our patients the patches are much smaller than the removed aneurysm and they were sutured simply by a single row of single stitches. However, in contrast to interventricular septum rupture where the patches loosen the tension of the tissues, in our patients the patches pull strongly and restrain the walls by fastening their edges and supporting tight stitches. In this way they could narrow the cavity and close the ventricle. RESULTS: The resected area varied from 5 × 4 to 8 × 8 cm. Excision was extended into the interventricular septum in 5 patients, thus opening the right ventricle. CABG was performed on all patients but two. Left ventricular volumes and the ejection fraction changed significantly: end-systolic volume 93.5 ± 12.4 to 57.8 ± 8.9 ml, p < 0.001; end-diastolic volume 157.2 ± 16.7 to 115.3 ± 14.9 ml, p < 0.001; ejection fraction 40.3 ± 4.2 to 49.5 ± 5.7%, p < 0.001. All patients did well. One patient suffered from bleeding, which was not from the wall suture, and another had a left arm paresis. The post-operative hospital stay was 5 to 30 days with a mean 10.5 ± 7.5 days/patient. At follow-up, 9 to 60 months mean 34, all patients were symptom-free. NYHA class 2.5 ± 0.8 changed to 1.2 ± 0.4, p < 0.001. CONCLUSION: The double-patch sandwich technique (bi-patch closure) offers some advantages and does not result in increased morbidity and mortality. In the case of excising a left ventricular aneurysm, this technique in no way requires eversion of the edges, felt strips, buttressed and multiple sutures, all of which are needed for longitudinal linear closure. Moreover, it does not require purse string sutures, endocardial scar remnant to secure the patch or folding the excluded non-functional tissue, all of which are needed for endoventricular patch repair