Genetic causes of heart failure with preserved ejection fraction: emerging pharmacological treatments.

Heart failure with preserved ejection fraction (HFpEF) is a major driver of cardiac morbidity and mortality in developed countries, due to ageing populations and the increasing prevalence of comorbidities. While heart failure with reduced ejection fraction is dominated by left ventricular impairment, HFpEF results from a complex interplay of cardiac remodelling, peripheral circulation, and concomitant features including age, hypertension, obesity, and diabetes. In an important subset, however, HFpEF is subtended by specific diseases of the myocardium that are genetically determined, have distinct pathophysiology, and are increasingly amenable to targeted, innovative treatments. While each of these conditions is rare, they collectively represent a relevant subset within HFpEF cohorts, and their prompt recognition has major consequences for clinical practice, as access to dedicated, disease-specific treatments may radically change the quality of life and outcome. Furthermore, response to standard heart failure treatment will generally be modest for these individuals, whose inclusion in registries and trials may dilute the perceived efficacy of treatments targeting mainstream HFpEF. Finally, a better understanding of the molecular underpinnings of monogenic myocardial disease may help identify therapeutic targets and develop innovative treatments for selected HFpEF phenotypes of broader epidemiological relevance. The field of genetic cardiomyopathies is undergoing rapid transformation due to recent, groundbreaking advances in drug development, and deserves greater awareness within the heart failure community. The present review addressed existing and developing therapies for genetic causes of HFpEF, including hypertrophic cardiomyopathy, cardiac amyloidosis, and storage diseases, discussing their potential impact on management and their broader implications for our understanding of HFpEF at large.

Clinical Outcomes in Patients With ST-Segment Elevation MI and No Standard Modifiable Cardiovascular Risk Factors.

BACKGROUND: The author recently reported ∼50% excess early mortality in patients with first-presentation ST-segment elevation myocardial infarction (STEMI) without standard modifiable cardiovascular risk factors (SMuRFs); the cause of this is not clear. OBJECTIVES: The aim of this study was to examine differences in infarct characteristics and clinical outcomes in patients with versus without SMuRFs (dyslipidemia, hypertension, diabetes mellitus, and smoking). METHODS: Individual-level data were pooled from 10 randomized percutaneous intervention (PCI) trials in which infarct size was measured within 1 month by either cardiac magnetic resonance or technetium-99m sestamibi single-photon emission computed tomography imaging. First-presentation STEMI was classified into 2 groups according to the presence or absence of at least 1 SMuRF. RESULTS: Among 2,862 patients, 524 (18.3%) were SMuRF-less. After adjusting for study effect, SMuRF-less patients had more frequent poor pre-PCI flow Thrombolysis In Myocardial Infarction 0/1 compared with patients with at least 1 SMuRF (72.0% vs 64.1%; OR: 1.35; 95% CI: 1.08-1.70). There were no independent associations between the presence or absence of SMuRFs at baseline and infarct size (estimate = -0.35; 95% CI: -1.93 to 1.23), left ventricular ejection fraction (estimate = -0.06; 95% CI: -1.33 to 1.20), or mortality at 30 days (HR: 0.46; 95% CI: 0.19-1.07) and 1 year (HR: 0.74; 95% CI: 0.43-1.29). CONCLUSIONS: First-presentation STEMI patients with no identifiable baseline SMuRFs had a higher risk of Thrombolysis In Myocardial Infarction flow grade 0/1 pre-PCI. However, after adjustment, there were no significant associations between SMuRF-less status and infarct size, left ventricle ejection fraction, or mortality.

Pulmonary Tumor Thrombotic Microangiopathy as a Cause of Pulmonary Hypertension.

Pulmonary tumor thrombotic microangiopathy is a rare entity, often diagnosed postmortem. We describe a patient with signs and symptoms of pulmonary hypertension secondary to metastatic cholangiocarcinoma with invasion of the myocardium and pulmonary vasculature, and highlight the diagnostic challenges and therapeutic limitations of this disease. (Level of Difficulty: Intermediate.).

Effect of Smoking on Outcomes of Primary PCI in Patients With STEMI.

BACKGROUND: Smoking is a well-established risk factor for ST-segment elevation myocardial infarction (STEMI); however, once STEMI occurs, smoking has been associated with favorable short-term outcomes, an observation termed the "smoker's paradox." It has been postulated that smoking might exert protective effects that could reduce infarct size, a strong independent predictor of worse outcomes after STEMI. OBJECTIVES: The purpose of this study was to determine the relationship among smoking, infarct size, microvascular obstruction (MVO), and adverse outcomes after STEMI. METHODS: Individual patient-data were pooled from 10 randomized trials of patients with STEMI undergoing primary percutaneous coronary intervention. Infarct size was assessed at median 4 days by either cardiac magnetic resonance imaging or technetium-99m sestamibi single-photon emission computed tomography. Multivariable analysis was used to assess the relationship between smoking, infarct size, and the 1-year rates of death or heart failure (HF) hospitalization and reinfarction. RESULTS: Among 2,564 patients with STEMI, 1,093 (42.6%) were recent smokers. Smokers were 10 years younger and had fewer comorbidities. Infarct size was similar in smokers and nonsmokers (adjusted difference: 0.0%; 95% confidence interval [CI]: -3.3% to 3.3%; p = 0.99). Nor was the extent of MVO different between smokers and nonsmokers. Smokers had lower crude 1-year rates of all-cause death (1.0% vs. 2.9%; p < 0.001) and death or HF hospitalization (3.3% vs. 5.1%; p = 0.009) with similar rates of reinfarction. After adjustment for age and other risk factors, smokers had a similar 1-year risk of death (adjusted hazard ratio [adjHR]: 0.92; 95% CI: 0.46 to 1.84) and higher risks of death or HF hospitalization (adjHR: 1.49; 95% CI: 1.09 to 2.02) as well as reinfarction (adjHR: 1.97; 95% CI: 1.17 to 3.33). CONCLUSIONS: In the present large-scale individual patient-data pooled analysis, recent smoking was unrelated to infarct size or MVO, but was associated with a worse prognosis after primary PCI in STEMI. The smoker's paradox may be explained by the younger age and fewer cardiovascular risk factors in smokers compared with nonsmokers.

Discordances between predicted and actual risk in obese patients with suspected cardiac ischaemia.

OBJECTIVES: To test the relationship between increasing severity of obesity, calculated risk and observed outcomes. METHODS: Patients with symptoms suggestive of coronary artery disease (CAD) (n=10 003) were stratified according to body mass index (BMI). We compared risk factors, pooled risk scores and physicians' perception of risk. Cox regression tested the association between BMI and (1) presence of obstructive CAD and (2) composite clinical endpoints (death, cardiovascular death, unstable angina hospitalisation and myocardial infarction). RESULTS: BMI was ≥30 kg/m2 in 48% of patients and ≥35 in 20%. Increasingly obese patients were younger, female and non-smoking but with higher prevalence of hypertension, diabetes, black race and sedentary lifestyle. Pooled risk estimates of CAD were highest in those with mid-range BMI. In contrast, physicians' estimation of the likelihood of significant CAD based on clinical impression increased progressively with BMI. For a 10% increase in the Diamond-Forrester probability of CAD, the adjusted OR for obstructive CAD was 1.5 (95% CI 1.4 to 1.5) in patients with BMI <35, but only 1.2 (95% CI 1.1 to 1.3) in those with BMI ≥35 (interaction p<0.001). Framingham Risk Score increased across increasing BMI categories. However, there was a strong and consistent inverse relationship between degree of obesity and all three composite clinical endpoints over a median 25 months of follow-up. CONCLUSIONS: Despite perceptions of higher risk and higher risk scores, increasingly obese patients had obstructive CAD less frequently than predicted and had fewer adverse clinical outcomes. There is a need for risk assessment tools and guidelines that account for obesity. TRIAL REGISTRATION NUMBER: NCT01174550.

Predictive Model for High-Risk Coronary Artery Disease.

BACKGROUND: Patients with high-risk coronary artery disease (CAD) may be difficult to identify. METHODS: Using the PROMISE (Prospective Multicenter Imaging Study for Evaluation of Chest Pain) cohort randomized to coronary computed tomographic angiography (n=4589), 2 predictive models were developed for high-risk CAD, defined as left main stenosis (≥50% stenosis) or either (1) ≥50% stenosis [50] or (2) ≥70% stenosis [70] of 3 vessels or 2-vessel CAD involving the proximal left anterior descending artery. Pretest predictors were examined using stepwise logistic regression and assessed for discrimination and calibration. RESULTS: High-risk CAD was identified in 6.6% [50] and 2.4% [70] of patients. Models developed to predict high-risk CAD discriminated well: [50], bias-corrected C statistic=0.73 (95% CI, 0.71-0.76); [70], bias-corrected C statistic=0.73 (95% CI, 0.68-0.77). Variables predictive of CAD in both models included family history of premature CAD, age, male sex, lower glomerular filtration rate, diabetes mellitus, elevated systolic blood pressure, and angina. Additionally, smoking history was predictive of [50] CAD and sedentary lifestyle of [70] CAD. Both models characterized high-risk CAD better than the Pooled Cohort Equation (area under the curve=0.70 and 0.71 for [50] and [70], respectively) and Diamond-Forrester risk scores (area under the curve=0.68 and 0.71, respectively). Both [50] and [70] CAD was associated with more frequent invasive interventions and adverse events than non-high-risk CAD (all P<0.0001). CONCLUSIONS: In contemporary practice, 2.4% to 6.6% of stable, symptomatic patients requiring noninvasive testing have high-risk CAD. A simple combination of pretest clinical variables improves prediction of high-risk CAD over traditional risk assessments. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01174550.

Cardiovascular Outcomes Assessment of the MitraClip in Patients with Heart Failure and Secondary Mitral Regurgitation: Design and rationale of the COAPT trial.

BACKGROUND: Patients with heart failure (HF) and symptomatic secondary mitral regurgitation (SMR) have a poor prognosis, with morbidity and mortality directly correlated with MR severity. Correction of isolated SMR with surgery is not well established in this population, and medical management remains the preferred approach in most patients. The Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial was designed to determine whether transcatheter mitral valve (MV) repair with the MitraClip device is safe and effective in patients with symptomatic HF and clinically significant SMR. STUDY DESIGN: The COAPT trial is a prospective, randomized, parallel-controlled, open-label multicenter study of the MitraClip device for the treatment of moderate-to-severe (3+) or severe (4+) SMR (as verified by an independent echocardiographic core laboratory) in patients with New York Heart Association class II-IVa HF despite treatment with maximally tolerated guideline-directed medical therapy (GDMT) who have been determined by the site's local heart team as not appropriate for MV surgery. A total of 614 eligible subjects were randomized in a 1:1 ratio to MV repair with the MitraClip plus GDMT versus GDMT alone. The primary effectiveness end point is recurrent HF hospitalizations through 24 months, analyzed when the last subject completes 12-month follow-up, powered to demonstrate superiority of MitraClip therapy. The primary safety end point is a composite of device-related complications at 12 months compared to a performance goal. Follow-up is ongoing, and the principal results are expected in late 2018. CONCLUSIONS: HF patients with clinically significant SMR who continue to be symptomatic despite optimal GDMT have limited treatment options and a poor prognosis. The randomized COAPT trial was designed to determine the safety and effectiveness of transcatheter MV repair with the MitraClip in symptomatic HF patients with moderate-to-severe or severe SMR.

Results of surgical septal myectomy for obstructive hypertrophic cardiomyopathy: the Tufts experience.

BACKGROUND: For over 50 years, surgical septal myectomy has been the preferred treatment for drug-refractory heart failure symptoms in patients with obstructive hypertrophic cardiomyopathy (HCM). Over this time in the United States, the majority of myectomy operations have been performed in a small number of select referral centers. METHODS: We have taken the opportunity to report results from the relatively new Tufts HCM Center and surgical program, incorporated 13 years ago, during which 507 myectomies (52±14 years of age; 56% male) were performed by one cardiothoracic surgeon, Dr. Hassan Rastegar. RESULTS: Resting left ventricular (LV) outflow gradients were reduced from 56±42 mmHg preoperatively to 1.2±6.8 mmHg on most recent echocardiogram 2.0±2.5 years after surgery, and 94% of patients showed clinical improvement to NYHA functional class I or II. The first 200 myectomies were performed without mortality or major complications. Among all patients, 30-day mortality rate was 0.8%. Over follow-up of 3.2±2.8 years, 11 patients died (four due to HCM causes) with long-term survival after myectomy of 94% at 5 years (95% CI: 89-96%) and 91% at 10 years (95% CI: 84-95%), which did not differ from the age- and gender-matched general U.S. population (log-rank P=0.9). CONCLUSIONS: This experience demonstrates that, with the appropriate support, new HCM surgical programs can provide patients successful relief of outflow obstruction, extended longevity and restored of quality of life.

Safety of coronary CT angiography and functional testing for stable chest pain in the PROMISE trial: A randomized comparison of test complications, incidental findings, and radiation dose.

BACKGROUND: Coronary computed tomography angiography (CTA) and functional testing strategies for stable chest pain yield similar outcomes; one aspect that may guide test choice is safety. METHODS: We compared test safety (test complications, incidental findings, and effective radiation dose) between CTA and functional testing as-tested in PROMISE (PROspective Multicenter Imaging Study for Evaluation of Chest Pain). In the subgroup whose physicians intended nuclear stress over other functional tests if randomized to the functional arm, we compared radiation dose of CTA versus nuclear stress and identified characteristics associated with dose. RESULTS: Of 9470 patients, none had major and <1% had minor complications (CTA: 0.8% [37/4633] vs. functional: 0.6% [27/4837]). CTA identified more incidental findings (11.6% [539/4633] vs. 0.7% [34/4837], p < 0.001), most commonly pulmonary nodules (9.4%, 437/4633). CTA had similar 90-day cumulative radiation dose to functional testing. However, in the subgroup whose physicians intended nuclear stress (CTA 3147; nuclear 3203), CTA had lower median index test (8.8 vs. 12.6 mSv, p < 0.001) and 90-day cumulative (11.6 vs. 13.1 mSv, p < 0.001) dose, independent of patient characteristics. The lowest nuclear doses employed 1-day Tc-99m protocols (12.2 mSv). The lowest CTA doses were at sites performing ≥500 CTAs/year (6.9 mSv) and with advanced (latest available) CT scanners (5.5 mSv). CONCLUSION: Complications were negligibly rare for both CTA and functional testing. CTA detects more incidental findings. Compared to nuclear stress testing, CTA's lower radiation dose, independent of patient characteristics, makes it an attractive test choice. Radiation dose varies with imaging protocol, indicating opportunities to further reduce dose. (ClinicalTrials.gov number, NCT01174550).

Short-Term Effects of Tolvaptan in Patients With Acute Heart Failure and Volume Overload.

BACKGROUND: In patients with acute heart failure (AHF), dyspnea relief is the most immediate goal. Renal dysfunction, diuretic resistance, and hyponatremia represent treatment impediments. OBJECTIVES: It was hypothesized that the addition of tolvaptan to a background diuretic improved dyspnea early in patients selected for an enhanced vasopressin antagonism response. METHODS: In a double-blind trial, patients were randomized to tolvaptan 30 mg/day or placebo. Study entry required hospitalization within the previous 36 h, active dyspnea, and any of the following: 1) estimated glomerular filtration rate <60 ml/min/1.73 m2; 2) hyponatremia; or 3) diuretic resistance (urine output ≤125 ml/h following intravenous furosemide ≥40 mg). The primary endpoint was a 7-point change in self-assessed dyspnea at 8 and 16 h, using a novel standardized approach. RESULTS: We randomized 250 patients. There was no difference in the primary endpoint of day 1 dyspnea reduction, despite significantly greater weight reduction with tolvaptan (-2.4 ± 2.1 kg vs. -0.9 ± 1.8 kg; p < 0.001). At day 3, dyspnea reduction was greater with tolvaptan (p = 0.01). There were 2 significant treatment-by-subgroup interactions: patients without elevated jugular venous pressure and those without ascites showed directional favorability of tolvaptan over placebo for the primary endpoint compared with patients with these findings. CONCLUSIONS: Despite rapid and persistent weight loss with tolvaptan compared with placebo, in patients with AHF who were selected for greater potential benefit from vasopressin receptor inhibition, tolvaptan was not associated with greater early improvement in dyspnea. Apparent subsequent differences in dyspnea warrant further exploration of the temporal relationship between diuresis and dyspnea relief and a possible clinical role for tolvaptan. (Randomized, Double-Blind, Placebo Controlled Study of the Short Term Clinical Effects of Tolvaptan in Patients Hospitalized for Worsening Heart Failure With Challenging Volume Management [SECRET of CHF]; NCT01584557).

Identification of Patients With Stable Chest Pain Deriving Minimal Value From Noninvasive Testing: The PROMISE Minimal-Risk Tool, A Secondary Analysis of a Randomized Clinical Trial.

Importance: Guidelines recommend noninvasive testing for patients with stable chest pain, although many subsequently have normal test results and no adverse clinical events. Objective: To describe a risk tool developed to use only pretest clinical data to identify patients with chest pain with normal coronary arteries and no clinical events during follow-up (minimal-risk cohort). Design, Setting, and Participants: This secondary analysis of a randomized, pragmatic comparative effectiveness trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain [PROMISE]) includes stable, symptomatic outpatients without known coronary artery disease referred for noninvasive testing at 193 sites in North America. Interventions: Patients were randomized to receive coronary computed tomography angiography (CCTA) vs functional testing. Main Outcomes and Measures: A low-risk tool was developed and internally validated from July 27, 2010, to September 19, 2013, in 4631 patients receiving CCTA as their initial test, with a median follow-up of 25 months. Logistic regression analysis was used to evaluate pretest variables to determine factors associated with minimal risk using a two-thirds random sample for model derivation (n = 3087) and a one-third sample for testing and validation (n = 1544). The model was then applied to the CCTA and functional testing arms, and test results and event rates were ascertained. Results: A total of 1243 of 4631 patients (26.8%) were in the minimal-risk cohort. The final minimal-risk model included 10 clinical variables that together were correlated with normal CCTA results and no clinical events (C statistic = 0.725 for the derivation and validation subsets; 95% CI, 0.705-0.746): younger age; female sex; racial or ethnic minority; no history of hypertension, diabetes, or dyslipidemia; family history of premature coronary artery disease; never smoking; symptoms unrelated to physical or mental stress; and higher high-density lipoprotein cholesterol level. Across the entire PROMISE cohort, this model was associated with the lowest rates of severely abnormal test results (1.3% for CCTA; 5.6% for functional) and cardiovascular death or myocardial infarction (0.5% for a median of 25 months) among patients at the highest probability (10th decile) of minimal risk. Conclusions and Relevance: In contemporary practice, more than 25% of patients with stable chest pain referred for noninvasive testing will have normal coronary arteries and no long-term clinical events. A clinical tool using readily available pretest variables discriminates such minimal-risk patients, for whom deferred testing may be considered. Trial Registration: clinicaltrials.gov Identifier: NCT01174550.

Rationale and design of the Randomized Evaluation of patients with Stable angina Comparing Utilization of noninvasive Examinations (RESCUE) trial.

RESCUE is a phase III, randomized, controlled, multicenter, comparative efficacy study, designed to compare two diagnostic imaging/treatment paradigms that use coronary computed tomography angiography (CCTA) or single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) for assisting in the diagnosis of ischemic heart disease in patients with stable angina symptoms, and guiding subsequent treatment. The study is based on the hypothesis that CCTA as a diagnostic tool is associated with no increase in cardiac risk, decreased cost, and reduced radiation exposure compared with SPECT MPI. The RESCUE trial was funded by the Agency for Healthcare Research and Quality (AHRQ) and the American College of Radiology Imaging Network (ACRIN) Fund for Imaging Innovation, began in 2011, and completed in 2014.

Relationship Between Infarct Size and Outcomes Following Primary PCI: Patient-Level Analysis From 10 Randomized Trials.

BACKGROUND: Prompt reperfusion in patients with ST-segment elevation myocardial infarction (STEMI) reduces infarct size and improves survival. However, the intuitive link between infarct size and prognosis has not been convincingly demonstrated in the contemporary era. OBJECTIVES: This study sought to determine the strength of the relationship between infarct size assessed early after primary percutaneous coronary intervention (PCI) in STEMI and subsequent all-cause mortality, reinfarction, and hospitalization for heart failure. METHODS: We performed a pooled patient-level analysis from 10 randomized primary PCI trials (total 2,632 patients) in which infarct size was assessed within 1 month after randomization by either cardiac magnetic resonance (CMR) imaging or technetium-99m sestamibi single-photon emission computed tomography (SPECT), with clinical follow-up for ≥ 6 months. RESULTS: Infarct size was assessed by CMR in 1,889 patients (71.8%) and by SPECT in 743 patients (28.2%). Median (25th, 75th percentile) time to infarct size measurement was 4 days (3, 10 days) after STEMI. Median infarct size (% left ventricular myocardial mass) was 17.9% (8.0%, 29.8%), and median duration of clinical follow-up was 352 days (185, 371 days). The Kaplan-Meier estimated 1-year rates of all-cause mortality, reinfarction, and HF hospitalization were 2.2%, 2.5%, and 2.6%, respectively. A strong graded response was present between infarct size (per 5% increase) and subsequent mortality (Cox-adjusted hazard ratio: 1.19 [95% confidence interval: 1.18 to 1.20]; p < 0.0001) and hospitalization for heart failure (adjusted hazard ratio: 1.20 [95% confidence interval: 1.19 to 1.21]; p < 0.0001), independent of age, sex, diabetes, hypertension, hyperlipidemia, current smoking, left anterior descending versus non-left anterior descending infarct vessel, symptom-to-first device time, and baseline TIMI (Thrombolysis In Myocardial Infarction) flow 0/1 versus 2/3. Infarct size was not significantly related to subsequent reinfarction. CONCLUSIONS: Infarct size, measured by CMR or technetium-99m sestamibi SPECT within 1 month after primary PCI, is strongly associated with all-cause mortality and hospitalization for HF within 1 year. Infarct size may, therefore, be useful as an endpoint in clinical trials and as an important prognostic measure when caring for patients with STEMI.

Significance of false negative electrocardiograms in preparticipation screening of athletes for hypertrophic cardiomyopathy.

Preparticipation screening of athletes with 12-lead electrocardiography has been promoted for the detection of asymptomatic cardiovascular disease, particularly hypertrophic cardiomyopathy (HC). Although false-positive electrocardiographic (ECG) results for HC are well recognized in athlete screening, expected false-negative rates are unknown. The aim of this study was to characterize the rate of false-negative ECG findings in a cohort of young asymptomatic patients with phenotypically expressed HC, defined by cardiovascular magnetic resonance, using the 2010 European Society of Cardiology recommended ECG criteria for the identification of suspected heart disease in trained athletes. Cardiac magnetic resonance studies and 12-lead electrocardiography were performed in 114 consecutive asymptomatic patients with HC aged ≤35 years (mean age 22 ± 8 years; 77% male patients). Electrocardiograms were analyzed to distinguish pathologic ECG patterns from alterations considered nonpathologic and physiologic consequences of athletic training. Among the 114 patients with HC, 103 (90%) demonstrated ≥1 pathologic ECG abnormality, while the remaining 11 patients (10%) had normal or nonpathologic ECG patterns and therefore defined a subgroup in whom ECG screening would not be expected to raise suspicion of heart disease (i.e., false-negative results). In this false-negative ECG results group, maximal left ventricular wall thickness was 17 ± 2 mm (range 15 to 21), compared to patients with pathologic ECG patterns, in whom maximal left ventricular wall thickness was 22 ± 5 mm (p = 0.003). In conclusion, a substantial minority of young asymptomatic patients with HC with phenotypically expressed left ventricular hypertrophy have nonpathologic ECG findings on the basis of the 2010 European Society of Cardiology guidelines. In principle, this high false-negative rate of 10% represents an important limitation in applying 12-lead electrocardiography to large, apparently healthy athletic populations for the detection of HC.