Physiologic Pacing for the Prevention and Treatment of Heart Failure A State-of-the-Art Review.

Permanent pacing from the right ventricular apex can reduce quality of life and increase the risk of heart failure and death. This review summarizes the milestones in the evolution of pacemakers towards "physiologic pacing" with biventricular pacing systems and lead implantation into the cardiac conduction system to synchronize cardiac contraction and relaxation. Both approaches aim to reproduce normal cardiac activation and help prevent and treat heart failure. This review introduces the basic concepts and clinical evidence and discusses practical uses of physiological pacing.

Rationale and design of the RAPID-WATER-FLOW trial: Radiolabeled perfusion to identify coronary artery disease using water to evaluate responses of myocardial FLOW.

OBJECTIVES: The objective of this study was to determine the diagnostic performance of 15O-water positron emission tomography (PET) myocardial perfusion imaging to detect coronary artery disease (CAD) using the truth-standard of invasive coronary angiography (ICA) with fractional flow reserve (FFR) or instantaneous wave-Free Ratio (iFR) or coronary computed tomography angiogram (CCTA). BACKGROUND: 15O-water has a very high first-pass extraction that allows accurate quantification of myocardial blood flow and detection of flow-limiting CAD. However, the need for an on-site cyclotron and lack of automated production at the point of care and relatively complex image analysis protocol has limited its clinical use to date. METHODS: The RAPID WATER FLOW study is an open-label, multicenter, prospective investigation of the accuracy of 15O-water PET to detect obstructive angiographic and physiologically significant stenosis in patients with suspected CAD. The study will include the use of an automated system for producing, dosing, and injecting 15O-water and enrolling approximately 215 individuals with suspected CAD at approximately 10 study sites in North America and Europe. The primary endpoint of the study is the diagnostic sensitivity and specificity of the 15O-water PET study using the truth-standard of ICA with FFR or iFR to determine flow-limiting stenosis, or CCTA to rule out CAD and incorporating a quantitative analytic platform developed for the 15O-water PET acquisitions. Sensitivity and specificity are to be considered positive if the lower bound of the 95% confidence interval is superior to the threshold of 60% for both, consistent with prior registration studies. Subgroup analyses include assessments of diagnostic sensitivity, specificity, and accuracy in female, obese, and diabetic individuals, as well as in those with multivessel disease. All enrolled individuals will be followed for adverse and serious adverse events for up to 32 hours after the index PET scan. The study will have >90% power (one-sided test, α = 0.025) to test the hypothesis that sensitivity and specificity of 15O-water PET are both >60%. CONCLUSIONS: The RAPID WATER FLOW study is a prospective, multicenter study to determine the diagnostic sensitivity and specificity of 15O-water PET as compared to ICA with FFR/iFR or CCTA. This study will introduce several novel aspects to imaging registration studies, including a more relevant truth standard incorporating invasive physiologic indexes, coronary CTA to qualify normal individuals for eligibility, and a more quantitative approach to image analysis than has been done in prior pivotal studies. CLINICAL TRIAL REGISTRATION INFORMATION: Clinical-Trials.gov (#NCT05134012).

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 and cost implications of deferred testing in low-risk patients with stable chest pain: a simulation using the PROMISE trial.

Current guidelines recommend a deferred testing approach in low-risk patients presenting with stable chest pain. After simulating a deferred testing approach using the PROMISE Minimal Risk Score to identify 915 minimal risk participants with cost data from the PROMISE trial, a deferred testing strategy was associated with an adjusted cost savings of -$748.74 (95% CI: -1646.97, 158.06) per participant and 74.6% of samples had better clinical outcomes and lower mean cost. This supports the current guideline recommended deferred testing approach in low-risk patients with stable chest pain.

Primary left ventricular unloading with delayed reperfusion in patients with anterior ST-elevation myocardial infarction: Rationale and design of the STEMI-DTU randomized pivotal trial.

BACKGROUND: Despite successful primary percutaneous coronary intervention (PCI) in ST-elevation myocardial infarction (STEMI), myocardial salvage is often suboptimal, resulting in large infarct size and increased rates of heart failure and mortality. Unloading of the left ventricle (LV) before primary PCI may reduce infarct size and improve prognosis. STUDY DESIGN AND OBJECTIVES: STEMI-DTU (NCT03947619) is a prospective, randomized, multicenter trial designed to compare mechanical LV unloading with the Impella CP device for 30 minutes prior to primary PCI to primary PCI alone without LV unloading. The trial aims to enroll approximately 668 subjects, with a potential sample size adaptation, with anterior STEMI with a primary end point of infarct size as a percent of LV mass evaluated by cardiac magnetic resonance at 3-5 days after PCI. The key secondary efficacy end point is a hierarchical composite of the 1-year rates of cardiovascular mortality, cardiogenic shock ≥24 hours after PCI, use of a surgical left ventricular assist device or heart transplant, heart failure, intra-cardiac defibrillator or chronic resynchronization therapy placement, and infarct size at 3 to 5 days post-PCI. The key secondary safety end point is Impella CP-related major bleeding or major vascular complications within 30 days. Clinical follow-up is planned for 5 years. CONCLUSIONS: STEMI-DTU is a large-scale, prospective, randomized trial evaluating whether mechanical unloading of the LV by the Impella CP prior to primary PCI reduces infarct size and improves prognosis in patients with STEMI compared to primary PCI alone without LV unloading.

The prospective randomized trial of the optimal evaluation of cardiac symptoms and revascularization: Rationale and design of the PRECISE trial.

BACKGROUND: Clinicians vary widely in their preferred diagnostic approach to patients with non-acute chest pain. Such variation exposes patients to potentially avoidable risks, as well as inefficient care with increased costs and unresolved patient concerns. METHODS: The Prospective Randomized Trial of the Optimal Evaluation of Cardiac Symptoms and Revascularization (PRECISE) trial (NCT03702244) compares an investigational "precision" diagnostic strategy to a usual care diagnostic strategy in participants with stable chest pain and suspected coronary artery disease (CAD). RESULTS: PRECISE randomized 2103 participants with stable chest pain and a clinical recommendation for testing for suspected CAD at 68 outpatient international sites. The investigational precision evaluation strategy started with a pre-test risk assessment using the PROMISE Minimal Risk Tool. Those at lowest risk were assigned to deferred testing (no immediate testing), and the remainder received coronary computed tomographic angiography (cCTA) with selective fractional flow reserve (FFRCT) for any stenosis meeting a threshold of ≥30% and <90%. For participants randomized to usual care, the clinical care team selected the initial noninvasive or invasive test (diagnostic angiography) according to customary practice. The use of cCTA as the initial diagnostic strategy was proscribed by protocol for the usual care strategy. The primary endpoint is time to a composite of major adverse cardiac events (MACE: all-cause death or non-fatal myocardial infarction) or invasive cardiac catheterization without obstructive CAD at 1 year. Secondary endpoints include health care costs and quality of life. CONCLUSIONS: PRECISE will determine whether a precision approach comprising a strategically deployed combination of risk-based deferred testing and cCTA with selective FFRCT improves the clinical outcomes and efficiency of the diagnostic evaluation of stable chest pain over usual care.

Rates of Reversal of Volume Overload in Hospitalized Acute Heart Failure: Association With Long-term Kidney Function.

RATIONALE & OBJECTIVE: Achievement of decongestion in acute heart failure (AHF) is associated with improved survival and cardiovascular outcomes but can be associated with acute declines in estimated glomerular filtration rate (eGFR). We examined whether the rate of in-hospital decongestion is associated with longer term kidney function decline. STUDY DESIGN: Post hoc analysis of trial data. SETTINGS & PARTICIPANTS: Patients with ≥2 measures of kidney function (n = 3,500) from the Efficacy of Vasopressin Antagonism in Heart Failure Outcome Study With Tolvaptan (EVEREST) trial. EXPOSURE: In-hospital rate of change in assessments of volume overload, including B-type natriuretic peptide (BNP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and clinical congestion score (0-12); and rate of change in hemoconcentration including measures of hematocrit, albumin, and total protein. OUTCOME: Incident chronic kidney disease GFR category 4 or worse (chronic kidney disease [CKD] categories G4-G5; defined by a new eGFR of <30 mL/min/1.73 m2) and eGFR decline of >40%. ANALYTICAL APPROACH: Multivariable cause-specific hazards models. RESULTS: Over median 10-month follow-up period, faster decreases in volume overload and more rapid increases in hemoconcentration were associated with a decreased risk of incident CKD G4-G5 and eGFR decline of >40%. In adjusted analyses, for every 6% faster decline in BNP per week, there was a 32% lower risk of both incident CKD G4-G5 (HR, 0.68 [95% CI, 0.58-0.79]) and eGFR decline of >40% (HR, 0.68 [95% CI, 0.57-0.80]). For every 1% faster increase per week in absolute hematocrit, there was a lower risk for both incident CKD G4-G5 (HR, 0.73 [95% CI, 0.64-0.84]) and eGFR decline of >40% (HR, 0.82 [95% CI, 0.71-0.95]), with results consistent for other biomarkers. LIMITATIONS: Possibility of residual confounding. CONCLUSIONS: These results provide reassurance that more rapid decongestion in patients with AHF does not increase the risk of adverse kidney outcomes in patients with heart failure.

Is heart failure with preserved ejection fraction a 'dementia' of the heart?

Heart failure with preserved ejection fraction (HFpEF) remains an elusive entity, due to its heterogeneous clinical profile and an arbitrarily defined nosology. Several pathophysiological mechanisms recognized as central for the development of HFpEF appear to be in common with the process of physiological aging of the heart. Both conditions are characterized by progressive impairment in cardiac function, accompanied by left ventricular hypertrophy, diastolic dysfunction, sarcomeric, and metabolic abnormalities. The neurological paradigm of dementia-intended as a progressive, multifactorial organ damage with decline of functional reserve, eventually leading to irreversible dysfunction-is well suited to represent HFpEF. In such perspective, certain phenotypes of HFpEF may be viewed as a maladaptive response to environmental modifiers, causing premature and pathological aging of the heart. We here propose that the 'HFpEF syndrome' may reflect the interplay of adverse structural remodelling and erosion of functional reserve, mirroring the processes leading to dementia in the brain. The resulting conceptual framework may help advance our understanding of HFpEF and unravel potential therapeutical targets.

Dual Vasopressin Receptor Antagonism to Improve Congestion in Patients With Acute Heart Failure: Design of the AVANTI Trial.

BACKGROUND: Loop diuretics are the main treatment for patients with acute heart failure, but are associated with neurohormonal stimulation and worsening renal function and do not improve long-term outcomes. Antagonists to arginine vasopressin may provide an alternative strategy to avoid these effects. The AVANTI study will investigate the efficacy and safety of pecavaptan, a novel, balanced dual-acting V1a/V2 vasopressin antagonist, both as adjunctive therapy to loop diuretics after admission for acute heart failure, and later as monotherapy. METHODS AND RESULTS: AVANTI is a double-blind, randomized phase II study in 571 patients hospitalized with acute heart failure and signs of persistent congestion before discharge. In part A, patients will receive either pecavaptan 30 mg/d or placebo with standard of care for 30 days. In part B, eligible patients will continue treatment or receive pecavaptan or diuretics as monotherapy for another 30 days. The primary end points for part A are changes in body weight and serum creatinine; for part B, changes in body weight and blood urea nitrogen/creatinine ratio. CONCLUSIONS: This study will provide the first evidence that a balanced V1a/V2 antagonist may safely enhance decongestion, both as an adjunct to loop diuretics and as an alternative strategy. TRIAL REGISTRATION NUMBER: NCT03901729.

Assessing myocardial perfusion in suspected coronary artery disease: rationale and design of the second phase 3, open-label multi-center study of flurpiridaz (F-18) injection for positron emission tomography (PET) imaging.

BACKGROUND: Positron emission tomography (PET) myocardial perfusion imaging (MPI) with the novel radiopharmaceutical Fluorine-18 Flurpiridaz has been shown in Phase 1, 2, and first Phase 3 clinical studies to be safe and effective in diagnosing coronary artery disease (CAD). We describe the methodology of the second FDA-mandated phase 3 prospective, open-label, international, multi-center trial of F-18 Flurpiridaz PET MPI. METHODS: The primary study end point is to assess the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD [≥ 50% by quantitative invasive coronary angiography (ICA)] in patients with suspected CAD. The secondary endpoints are to evaluate the diagnostic efficacy of F-18 Flurpiridaz PET MPI compared to Tc-99 m-labeled SPECT MPI in the detection of CAD in all patients and in the following subgroups: (1) females; (2) patients with body mass index ≥ 30 kg/m2; and (3) diabetic patients. This trial's design differs from the first phase 3 trial in that (1) comparison to SPECT is now a secondary end point; (2) patients with known CAD are excluded; and (3) both SPECT and PET MPI are performed before ICA. CONCLUSIONS: This second phase 3 study will provide additional evidence on the diagnostic efficacy of F-18 Flurpiridaz PET MPI in the detection of significant CAD. TRIAL REGISTRATION NUMBER: NCT03354273.

Unloading the Left Ventricle Before Reperfusion in Patients With Anterior ST-Segment-Elevation Myocardial Infarction.

BACKGROUND: In ST-segment-elevation myocardial infarction (STEMI), infarct size correlates directly with heart failure and mortality. Preclinical testing has shown that, in comparison with reperfusion alone, mechanically unloading the left ventricle (LV) before reperfusion reduces infarct size and that 30 minutes of unloading activates a cardioprotective program that limits reperfusion injury. The DTU-STEMI pilot trial (Door-To-Unload in STEMI Pilot Trial) represents the first exploratory study testing whether LV unloading and delayed reperfusion in patients with STEMI without cardiogenic shock is safe and feasible. METHODS: In a multicenter, prospective, randomized exploratory safety and feasibility trial, we assigned 50 patients with anterior STEMI to LV unloading by using the Impella CP followed by immediate reperfusion (U-IR) versus delayed reperfusion after 30 minutes of unloading (U-DR). The primary safety outcome was a composite of major adverse cardiovascular and cerebrovascular events at 30 days. Efficacy parameters included the assessment of infarct size by using cardiac magnetic resonance imaging. RESULTS: All patients completed the U-IR (n=25) or U-DR (n=25) protocols with respective mean door-to-balloon times of 72 versus 97 minutes. Major adverse cardiovascular and cerebrovascular event rates were not statistically different between the U-IR versus U-DR groups (8% versus 12%, respectively, P=0.99). In comparison with the U-IR group, delaying reperfusion in the U-DR group did not affect 30-day mean infarct size measured as a percentage of LV mass (15±12% versus 13±11%, U-IR versus U-DR, P=0.53). CONCLUSIONS: We report that LV unloading using the Impella CP device with a 30-minute delay before reperfusion is feasible within a relatively short time period in anterior STEMI. The DTU-STEMI pilot trial did not identify prohibitive safety signals that would preclude proceeding to a larger pivotal study of LV unloading before reperfusion. An appropriately powered pivotal trial comparing LV unloading before reperfusion to the current standard of care is required. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov . Unique identifier: NCT03000270.

Rationale and design for a multicenter, randomized, double-blind, placebo-controlled, phase 2 study evaluating the safety and efficacy of the soluble guanylate cyclase stimulator praliciguat over 12 weeks in patients with heart failure with preserved ejection fraction (CAPACITY HFpEF).

BACKGROUND: Heart failure with preserved ejection fraction (HFpEF) is a significant cause of morbidity and mortality worldwide. Exercise intolerance is the main symptom of HFpEF and is associated with a poor quality of life and increased mortality. Currently, there are no approved medications for the treatment of HFpEF. Praliciguat (IW-1973), a novel soluble guanylate cyclase stimulator that may help restore deficient nitric oxide-soluble guanylate cyclase-cyclic guanosine 3',5'-monophosphate signaling, is being investigated for the treatment of patients with HFpEF. METHODS: CAPACITY HFpEF is a phase 2, multicenter, randomized, double-blind, placebo-controlled, parallel-group trial designed to evaluate the safety and efficacy of praliciguat over 12 weeks in approximately 184 patients with HFpEF. Eligible patients must have evidence supporting clinical HFpEF and at least 2 of the following 4 conditions associated with NO deficiency: diabetes/prediabetes, hypertension, obesity, and age >70 years. The primary efficacy end point is the change from baseline in peak VO2 by cardiopulmonary exercise test (CPET). Secondary end points include the change from baseline in 6-minute walk test distance and the change in ventilatory efficiency on CPET, as well as number of CPET responders. Other exploratory end points include changes in echocardiographic parameters, New York Heart Association functional classification, cardiac events, blood and urine biomarkers pathophysiologically relevant to heart failure, and patient-reported outcomes including Kansas City Cardiomyopathy Questionnaire. CONCLUSIONS: The CAPACITY HFpEF trial will provide data on short-term safety and efficacy of praliciguat on peak exercise capacity, as well as multiple secondary end points of submaximal functional capacity, patient-reported outcomes, and biomarkers.

Effects of Elamipretide on Left Ventricular Function in Patients With Heart Failure With Reduced Ejection Fraction: The PROGRESS-HF Phase 2 Trial.

BACKGROUND: Elamipretide, a novel mitochondrial modulating agent, improves myocardial energetics; however, it is unknown whether this mechanistic benefit translates into improved cardiac structure and function in heart failure (HF) with reduced ejection fraction (HFrEF). The objective of this study was to evaluate the effects of multiple subcutaneous doses of elamipretide on left ventricular end systolic volume (LVESV) as assessed by cardiac magnetic resonance imaging. METHODS: We randomized 71 patients with HFrEF (LVEF ≤ 40%) in a double-blind, placebo-controlled trial in a 1:1:1 ratio to receive placebo, 4 mg or 40 mg elamipretide once daily for 28 consecutive days. RESULTS: The mean age (standard deviation) of the study population was 65 ± 10 years, 24% were females, and the mean EF was 31% ± 7%. The change in LVESV from baseline to week 4 was not significantly different between elamipretide 4 mg (89.4 mL to 85 mL; difference, -4.4 mL) or 40 mg (77.9 mL to 76.6 mL; difference, -1.2 mL) compared with placebo (77.7 mL to 74.6 mL; difference, -3.8 mL) (4 mg vs placebo: difference of means, -0.3; 95% CI, -4.6 to 4.0; P = 0.90; and 40 mg vs placebo: difference of means, 2.3; 95% CI, -1.9 to 6.5; P  =  0.28). Also, no significant differences in change in LVESV and LVEF were observed between placebo and either of the elamipretide groups. Rates of any study drug-related adverse events were similar in the 3 groups. CONCLUSIONS: Elamipretide was well tolerated but did not improve LVESV at 4 weeks in patients with stable HFrEF compared with placebo.

TESTING OUR TESTS: THE EVOLUTION OF EVIDENCE FOR CARDIAC IMAGING.

While technical advances in cardiac imaging have been quite substantial, the true efficacy of imaging and how the resulting data affect patients and outcomes have been questioned. A six-level framework has been proposed for critically assessing the value of imaging. This report traces the evolution of cardiac imaging through the prism of this framework to demonstrate that cardiac imaging in contemporary practice is often supported by evidence from rigorous randomized trials.

Effect of Praliciguat on Peak Rate of Oxygen Consumption in Patients With Heart Failure With Preserved Ejection Fraction: The CAPACITY HFpEF Randomized Clinical Trial.

Importance: Heart failure with preserved ejection fraction (HFpEF) is often characterized by nitric oxide deficiency. Objective: To evaluate the efficacy and adverse effects of praliciguat, an oral soluble guanylate cyclase stimulator, in patients with HFpEF. Design, Setting, and Participants: CAPACITY HFpEF was a randomized, double-blind, placebo-controlled, phase 2 trial. Fifty-nine sites enrolled 196 patients with heart failure and an ejection fraction of at least 40%, impaired peak rate of oxygen consumption (peak V̇o2), and at least 2 conditions associated with nitric oxide deficiency (diabetes, hypertension, obesity, or advanced age). The trial randomized patients to 1 of 3 praliciguat dose groups or a placebo group, but was refocused early to a comparison of the 40-mg praliciguat dose vs placebo. Participants were enrolled from November 15, 2017, to April 30, 2019, with final follow-up on August 19, 2019. Interventions: Patients were randomized to receive 12 weeks of treatment with 40 mg of praliciguat daily (n = 91) or placebo (n = 90). Main Outcomes and Measures: The primary efficacy end point was the change from baseline in peak V̇o2 in patients who completed at least 8 weeks of assigned dosing. Secondary end points included the change from baseline in 6-minute walk test distance and in ventilatory efficiency (ventilation/carbon dioxide production slope). The primary adverse event end point was the incidence of treatment-emergent adverse events (TEAEs). Results: Among 181 patients (mean [SD] age, 70 [9] years; 75 [41%] women), 155 (86%) completed the trial. In the placebo (n = 78) and praliciguat (n = 65) groups, changes in peak V̇o2 were 0.04 mL/kg/min (95% CI, -0.49 to 0.56) and -0.26 mL/kg/min (95% CI, -0.83 to 0.31), respectively; the placebo-adjusted least-squares between-group difference in mean change from baseline was -0.30 mL/kg/min ([95% CI, -0.95 to 0.35]; P = .37). None of the 3 prespecified secondary end points were statistically significant. In the placebo and praliciguat groups, changes in 6-minute walk test distance were 58.1 m (95% CI, 26.1-90.1) and 41.4 m (95% CI, 8.2-74.5), respectively; the placebo-adjusted least-squares between-group difference in mean change from baseline was -16.7 m (95% CI, -47.4 to 13.9). In the placebo and praliciguat groups, the placebo-adjusted least-squares between-group difference in mean change in ventilation/carbon dioxide production slope was -0.3 (95% CI, -1.6 to 1.0). There were more dizziness (9.9% vs 1.1%), hypotension (8.8% vs 0%), and headache (11% vs 6.7%) TEAEs with praliciguat compared with placebo. The frequency of serious TEAEs was similar between the groups (10% in the praliciguat group and 11% in the placebo group). Conclusions and Relevance: Among patients with HFpEF, the soluble guanylate cyclase stimulator praliciguat, compared with placebo, did not significantly improve peak V̇o2 from baseline to week 12. These findings do not support the use of praliciguat in patients with HFpEF. Trial Registration: ClinicalTrials.gov Identifier: NCT03254485.

Prognostic Value of Noninvasive Cardiovascular Testing in Patients With Stable Chest Pain: Insights From the PROMISE Trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain).

BACKGROUND: Optimal management of patients with stable chest pain relies on the prognostic information provided by noninvasive cardiovascular testing, but there are limited data from randomized trials comparing anatomic with functional testing. METHODS: In the PROMISE trial (Prospective Multicenter Imaging Study for Evaluation of Chest Pain), patients with stable chest pain and intermediate pretest probability for obstructive coronary artery disease (CAD) were randomly assigned to functional testing (exercise electrocardiography, nuclear stress, or stress echocardiography) or coronary computed tomography angiography (CTA). Site-based diagnostic test reports were classified as normal or mildly, moderately, or severely abnormal. The primary end point was death, myocardial infarction, or unstable angina hospitalizations over a median follow-up of 26.1 months. RESULTS: Both the prevalence of normal test results and incidence rate of events in these patients were significantly lower among 4500 patients randomly assigned to CTA in comparison with 4602 patients randomly assigned to functional testing (33.4% versus 78.0%, and 0.9% versus 2.1%, respectively; both P<0.001). In CTA, 54.0% of events (n=74/137) occurred in patients with nonobstructive CAD (1%-69% stenosis). Prevalence of obstructive CAD and myocardial ischemia was low (11.9% versus 12.7%, respectively), with both findings having similar prognostic value (hazard ratio, 3.74; 95% confidence interval [CI], 2.60-5.39; and 3.47; 95% CI, 2.42-4.99). When test findings were stratified as mildly, moderately, or severely abnormal, hazard ratios for events in comparison with normal tests increased proportionally for CTA (2.94, 7.67, 10.13; all P<0.001) but not for corresponding functional testing categories (0.94 [P=0.87], 2.65 [P=0.001], 3.88 [P<0.001]). The discriminatory ability of CTA in predicting events was significantly better than functional testing (c-index, 0.72; 95% CI, 0.68-0.76 versus 0.64; 95% CI, 0.59-0.69; P=0.04). If 2714 patients with at least an intermediate Framingham Risk Score (>10%) who had a normal functional test were reclassified as being mildly abnormal, the discriminatory capacity improved to 0.69 (95% CI, 0.64-0.74). CONCLUSIONS: Coronary CTA, by identifying patients at risk because of nonobstructive CAD, provides better prognostic information than functional testing in contemporary patients who have stable chest pain with a low burden of obstructive CAD, myocardial ischemia, and events. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01174550.

Outcomes of anatomical versus functional testing for coronary artery disease.

BACKGROUND: Many patients have symptoms suggestive of coronary artery disease (CAD) and are often evaluated with the use of diagnostic testing, although there are limited data from randomized trials to guide care. METHODS: We randomly assigned 10,003 symptomatic patients to a strategy of initial anatomical testing with the use of coronary computed tomographic angiography (CTA) or to functional testing (exercise electrocardiography, nuclear stress testing, or stress echocardiography). The composite primary end point was death, myocardial infarction, hospitalization for unstable angina, or major procedural complication. Secondary end points included invasive cardiac catheterization that did not show obstructive CAD and radiation exposure. RESULTS: The mean age of the patients was 60.8±8.3 years, 52.7% were women, and 87.7% had chest pain or dyspnea on exertion. The mean pretest likelihood of obstructive CAD was 53.3±21.4%. Over a median follow-up period of 25 months, a primary end-point event occurred in 164 of 4996 patients in the CTA group (3.3%) and in 151 of 5007 (3.0%) in the functional-testing group (adjusted hazard ratio, 1.04; 95% confidence interval, 0.83 to 1.29; P=0.75). CTA was associated with fewer catheterizations showing no obstructive CAD than was functional testing (3.4% vs. 4.3%, P=0.02), although more patients in the CTA group underwent catheterization within 90 days after randomization (12.2% vs. 8.1%). The median cumulative radiation exposure per patient was lower in the CTA group than in the functional-testing group (10.0 mSv vs. 11.3 mSv), but 32.6% of the patients in the functional-testing group had no exposure, so the overall exposure was higher in the CTA group (mean, 12.0 mSv vs. 10.1 mSv; P<0.001). CONCLUSIONS: In symptomatic patients with suspected CAD who required noninvasive testing, a strategy of initial CTA, as compared with functional testing, did not improve clinical outcomes over a median follow-up of 2 years. (Funded by the National Heart, Lung, and Blood Institute; PROMISE ClinicalTrials.gov number, 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.