Braunwald, Eugene

Background Soluble ST2 is a biomarker that is elevated in certain systemic inflammatory diseases. Comorbidity‐driven microvascular inflammation is postulated to play a key role in heart failure with preserved ejection fraction ( HF p EF ) pathophysiology, but data on how sST 2 relates to clinical characteristics or inflammatory conditions or biomarkers in HF p EF are limited. We sought to determine circulating levels and clinical correlates of sST 2 in HF pEF. Methods and Results At enrollment, patients (n=174) from the Phosphodiesterase‐5 Inhibition to Improve Clinical Status And Exercise Capacity in Diastolic Heart Failure (RELAX) trial of sildenafil in HF p EF had sST 2 levels measured. Clinical characteristics; cardiac structure and function; exercise performance; and biomarkers of neurohumoral activation, systemic inflammation and fibrosis, and myocardial necrosis were assessed in relation to sST 2 levels. Median sST 2 levels in male and female HFpEF patients were 36.7 ng/mL (range 30.9–49.2 ng/mL; reference range 4–31 ng/mL) and 30.8 ng/mL (range 25.3–39.3 ng/mL; reference range 2–21 ng/mL), respectively. Among HF p EF patients, higher sST 2 levels were associated with the presence of diabetes mellitus; atrial fibrillation; renal dysfunction; right ventricular pressure overload and dysfunction; systemic congestion; exercise intolerance; and biomarkers of systemic inflammation and fibrosis, neurohumoral activation, and myocardial necrosis ( P <0.05 for all). sST 2 was not associated with left ventricular structure or left ventricular systolic or diastolic function. Conclusions In HF p EF , sST 2 levels were associated with proinflammatory comorbidities, right ventricular pressure overload and dysfunction, and systemic congestion but not with left ventricular geometry or function. These data suggest that sST2 may be a marker of systemic inflammation in HF p EF and potentially of extracardiac origin. Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 00763867.

Background— Exercise intolerance is a hallmark of heart failure, but factors associated with impaired exercise capacity in heart failure with preserved ejection fraction are unclear. We hypothesized that in heart failure with preserved ejection fraction, the severity of resting ventricular and vascular dysfunction are associated with impairment in exercise tolerance as assessed by peak oxygen consumption. Methods and Results— Subjects with heart failure with preserved ejection fraction enrolled in the PhosphodiesteRasE-5 Inhibition to Improve CLinical Status And EXercise Capacity in Diastolic Heart Failure (RELAX) clinical trial (n=216) underwent baseline Doppler echocardiography, cardiopulmonary exercise testing, and cardiac MRI. RELAX participants were elderly (median age 69 years) and 48% were women. Ejection fraction (60%) and stroke volume (77 mL) were normal, while diastolic dysfunction (medial E / e ′, 16; deceleration time, 185 ms; left atrial volume, 44 mL/m 2 ) and increased arterial load (arterial elastance, 1.51 mm Hg/mL) were evident. Peak oxygen consumption was reduced (11.7 mLkg −1 min −1 , 1141 mL/min) and age, sex, body mass index, hemoglobin, and chronotropic response collectively explained 64% of the variance in raw peak oxygen consumption (mL/min). After adjustment for these variables, left ventricular structure (diastolic dimension [1.5%, P =0.008] and left ventricular mass [1.6%, P =0.008]), resting stroke volume (2.0%, P =0.002), left ventricular diastolic dysfunction (deceleration time [0.9%, P =0.03] and E / e ′ [1.4%, P =0.009]), and arterial function (arterial elastance [2.1%, P =0.002] and systemic arterial compliance [1.5%, P =0.007]), each explained only a small additional portion of the variance in peak oxygen consumption. Conclusions— In heart failure with preserved ejection fraction, potentially modifiable factors (obesity, anemia, and chronotropic incompetence) are strongly associated with exercise capacity, whereas resting measures of ventricular and vascular structure and function are not. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00763867

Background— Atrial fibrillation (AF) is common among patients with heart failure and preserved ejection fraction (HFpEF), but its clinical profile and impact on exercise capacity remain unclear. RELAX (Phosphodiesterase-5 Inhibition to Improve Clinical Status and Exercise Capacity in HFpEF) was a multicenter randomized trial testing the impact of sildenafil on peak V O 2 in stable outpatients with chronic HFpEF. We sought to compare clinical features and exercise capacity among patients with HFpEF who were in sinus rhythm (SR) or AF. Methods and Results— RELAX enrolled 216 patients with HFpEF, of whom 79 (37%) were in AF, 124 (57%) in SR, and 13 in other rhythms. Participants underwent baseline cardiopulmonary exercise testing, echocardiogram, biomarker assessment, and rhythm status assessment before randomization. Patients with AF were older than those in SR but had similar symptom severity, comorbidities, and renal function. β-blocker use and chronotropic indices were also similar. Despite comparable left ventricular size and mass, AF was associated with worse systolic (lower EF, stroke volume, and cardiac index) and diastolic (shorter deceleration time and larger left atria) function compared with SR. Pulmonary artery systolic pressure was higher in AF. Patients with AF had higher N-terminal pro-B-type natriuretic peptide, aldosterone, endothelin-1, troponin I, and C-telopeptide for type I collagen levels, suggesting more severe neurohumoral activation, myocyte necrosis, and fibrosis. Peak V O 2 was lower in AF, even after adjustment for age, sex, and chronotropic response, and V E /V CO 2 was higher. Conclusions— AF identifies an HFpEF cohort with more advanced disease and significantly reduced exercise capacity. These data suggest that evaluation of the impact of different rate or rhythm control strategies on exercise tolerance in patients with HFpEF and AF is warranted. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00763867.

Background There are few data comparing clinical outcome and potential indications for routine post–myocardial infarction cardiac catheterization and revascularization of patients who sustain a non–Q-wave versus Q-wave infarct after thrombolytic therapy. Methods and Results A secondary analysis of 2634 patients enrolled in the TIMI II trial with a first myocardial infarction was performed to determine 6-week and 1-year cardiac event rates and identify clinical and angiographic differences between the 1867 patients (70.9%) who evolved a Q-wave infarct and the 767 patients (29.1%) who sustained a non–Q-wave infarct after treatment with intravenous thrombolytic therapy. Male sex (85.3% versus 75.6%; P <.001) and anterior wall infarcts (53.8% versus 43.7%; P <.001) were more frequent in the Q-wave versus the non–Q-wave group. During recombinant tissue-type plasminogen activator (rTPA) infusion, a greater percentage of non–Q-wave patients (37.3% versus 23.5%; P =.001) had normalization of initial ST-segment elevation. Infarct-related artery patency (TIMI flow grade 2 or 3) ( P =.02), complete infarct-related artery reperfusion (TIMI 3 flow grade) ( P <.001), and the percentage of patients with a predischarge resting left ventricular ejection fraction >55% ( P <.001) were greater in the non–Q-wave group. New congestive heart failure during hospitalization developed more frequently in Q-wave patients (18.9% versus 11.6%; P <.001). After 42 days, the occurrences of reinfarction ( P =.76), death ( P =.76), and combined death or reinfarction ( P =.43) were similar in patients assigned to the invasive or conservative postlytic management strategy, regardless of infarct type. One-year mortality was 3.4% versus 4.4% for non–Q-wave versus Q-wave infarct type, respectively ( P =.25). Conclusions Angiographic and clinical differences were observed between patients who present with initial ST-segment elevation and evolve early non–Q-wave versus Q-wave myocardial infarcts after treatment with rTPA, heparin, and aspirin. Early mortality and adverse clinical cardiac events in these patients are not significantly different after a conservative compared with an invasive treatment strategy, regardless of whether the infarct type is non–Q wave or Q wave.

Background— Patients with chronic kidney disease are at increased risk for cardiovascular morbidity and mortality. We assessed the association between albuminuria and the risks for death and cardiovascular events among patients with stable coronary disease. Methods and Results— We studied patients enrolled in the Prevention of Events with an ACE inhibitor (PEACE) trial, in which patients with chronic stable coronary disease and preserved systolic function were randomized to trandolapril or placebo and followed up for a median of 4.8 years. The urinary albumin to creatinine ratio (ACR) assessed in a core laboratory in 2977 patients at baseline and in 1339 patients at follow-up (mean 34 months) was related to estimated glomerular filtration rate and outcomes. The majority of patients (73%) had a baseline ACR within the normal range (<17 μg/mg for men and <25 μg/mg for women). Independent of the estimated glomerular filtration rate and other baseline covariates, a higher ACR, even within the normal range, was associated with increased risks for all-cause mortality ( P <0.001) and cardiovascular death ( P =0.01). The effect of trandolapril therapy on outcomes was not modified significantly by the level of albuminuria. Nevertheless, trandolapril therapy was associated with a significantly lower mean follow-up ACR (12.5 versus 14.6 μg/mg, P =0.0002), after adjustment for baseline ACR, time between collections, and other covariates. An increase in ACR over time was associated with increased risk of cardiovascular death (hazard ratio per log ACR 1.74, 95% CI 1.08 to 2.82). Conclusions— Albuminuria, even in low levels within the normal range, is an independent predictor of cardiovascular and all-cause mortality.

Background— Ranolazine, a piperazine derivative, reduces ischemia via inhibition of the late phase of the inward sodium current (late I Na ) during cardiac repolarization, with a consequent reduction in intracellular sodium and calcium overload. Increased intracellular calcium leads to both mechanical dysfunction and electric instability. Ranolazine reduces proarrhythmic substrate and triggers such as early afterdepolarization in experimental models. However, the potential antiarrhythmic actions of ranolazine have yet to be demonstrated in humans. Methods and Results— The Metabolic Efficiency With Ranolazine for Less Ischemia in Non–ST-Elevation Acute Coronary Syndrome (MERLIN)–Thrombolysis in Myocardial Infarction (TIMI) 36 (MERLIN-TIMI 36) trial randomized 6560 patients hospitalized with a non–ST-elevation acute coronary syndrome to ranolazine or placebo in addition to standard therapy. Continuous ECG (Holter) recording was performed for the first 7 days after randomization. A prespecified set of arrhythmias were evaluated by a core laboratory blinded to treatment and outcomes. Of the 6560 patients in MERLIN-TIMI 36, 6351 (97%) had continuous ECG recordings that could be evaluated for arrhythmia analysis. Treatment with ranolazine resulted in significantly lower incidences of arrhythmias. Specifically, fewer patients had an episode of ventricular tachycardia lasting ≥8 beats (166 [5.3%] versus 265 [8.3%]; P <0.001), supraventricular tachycardia (1413 [44.7%] versus 1752 [55.0%]; P <0.001), or new-onset atrial fibrillation (55 [1.7%] versus 75 [2.4%]; P =0.08). In addition, pauses ≥3 seconds were less frequent with ranolazine (97 [3.1%] versus 136 [4.3%]; P =0.01). Conclusions— Ranolazine, an inhibitor of late I Na , appears to have antiarrhythmic effects as assessed by continuous ECG monitoring of patients in the first week after admission for acute coronary syndrome. Studies specifically designed to evaluate the potential role of ranolazine as an antiarrhythmic agent are warranted.