Invasive Cardiac Hemodynamics in Apical Hypertrophic Cardiomyopathy.

BACKGROUND: Symptomatic limitations in apical hypertrophic cardiomyopathy may occur because of diastolic dysfunction with resultant elevated left ventricular filling pressures, cardiac output limitation to exercise, pulmonary hypertension (PH), valvular abnormalities, and/or arrhythmias. In this study, the authors aimed to describe invasive cardiac hemodynamics in a cohort of patients with apical hypertrophic cardiomyopathy. METHODS AND RESULTS: Patients presenting to a comprehensive hypertrophic cardiomyopathy center with apical hypertrophic cardiomyopathy were identified (n=542) and those who underwent invasive hemodynamic catheterization (n=47) were included in the study. Of these, 10 were excluded due to postmyectomy status or incomplete hemodynamic data. The mean age was 56±18 years, 16 (43%) were women, and ejection fraction was preserved (≥50%) in 32 (91%) patients. The most common indication for catheterization was dyspnea (48%) followed by suspected PH (13%), and preheart transplant evaluation (10%). Elevated left ventricular filling pressures at rest or exercise were present in 32 (86%) patients. PH was present in 30 (81%) patients, with 6 (20%) also having right-sided heart failure. Cardiac index was available in 25 (86%) patients with elevated resting filling pressures. Of these, 19 (76%) had reduced cardiac index and all 6 with right-sided heart failure had reduced cardiac index. Resting hemodynamics were normal in 8 of 37 (22%) patients, with 5 during exercise; 3 of 5 (60%) patients had exercise-induced elevation in left ventricular filling pressures. CONCLUSIONS: In patients with apical hypertrophic cardiomyopathy undergoing invasive hemodynamic cardiac catheterization, 86% had elevated left ventricular filling pressures at rest or with exercise, 81% had PH, and 20% of those with PH had concomitant right-sided heart failure.

Predicting postoperative systolic dysfunction in mitral regurgitation: CT vs. echocardiography.

Introduction: Volume overload from mitral regurgitation can result in left ventricular systolic dysfunction. To prevent this, it is essential to operate before irreversible dysfunction occurs, but the optimal timing of intervention remains unclear. Current echocardiographic guidelines are based on 2D linear measurement thresholds only. We compared volumetric CT-based and 2D echocardiographic indices of LV size and function as predictors of post-operative systolic dysfunction following mitral repair. Methods: We retrospectively identified patients with primary mitral valve regurgitation who underwent repair between 2005 and 2021. Several indices of LV size and function measured on preoperative cardiac CT were compared with 2D echocardiography in predicting post-operative LV systolic dysfunction (LVEFecho <50%). Area under the curve (AUC) was the primary metric of predictive performance. Results: A total of 243 patients were included (mean age 57 ± 12 years; 65 females). The most effective CT-based predictors of post-operative LV systolic dysfunction were ejection fraction [LVEFCT; AUC 0.84 (95% CI: 0.77-0.92)] and LV end systolic volume indexed to body surface area [LVESViCT; AUC 0.88 (0.82-0.95)]. The best echocardiographic predictors were LVEFecho [AUC 0.70 (0.58-0.82)] and LVESDecho [AUC 0.79 (0.70-0.89)]. LVEFCT was a significantly better predictor of post-operative LV systolic dysfunction than LVEFecho (p = 0.02) and LVESViCT was a significantly better predictor than LVESDecho (p = 0.03). Ejection fraction measured by CT demonstrated significantly greater reproducibility than echocardiography. Discussion: CT-based volumetric measurements may be superior to established 2D echocardiographic parameters for predicting LV systolic dysfunction following mitral valve repair. Validation with prospective study is warranted.

Machine Learning for Diagnosis of Pulmonary Hypertension by Echocardiography.

OBJECTIVE: To evaluate a machine learning (ML)-based model for pulmonary hypertension (PH) prediction using measurements and impressions made during echocardiography. METHODS: A total of 7853 consecutive patients with right-sided heart catheterization and transthoracic echocardiography performed within 1 week from January 1, 2012, through December 31, 2019, were included. The data were split into training (n=5024 [64%]), validation (n=1275 [16%]), and testing (n=1554 [20%]). A gradient boosting machine with enumerated grid search for optimization was selected to allow missing data in the boosted trees without imputation. The training target was PH, defined by right-sided heart catheterization as mean pulmonary artery pressure above 20 mm Hg; model performance was maximized relative to area under the receiver operating characteristic curve using 5-fold cross-validation. RESULTS: Cohort age was 64±14 years; 3467 (44%) were female, and 81% (6323/7853) had PH. The final trained model included 19 characteristics, measurements, or impressions derived from the echocardiogram. In the testing data, the model had high discrimination for the detection of PH (area under the receiver operating characteristic curve, 0.83; 95% CI, 0.80 to 0.85). The model's accuracy, sensitivity, positive predictive value, and negative predictive value were 82% (1267/1554), 88% (1098/1242), 89% (1098/1241), and 54% (169/313), respectively. CONCLUSION: By use of ML, PH could be predicted on the basis of clinical and echocardiographic variables, without tricuspid regurgitation velocity. Machine learning methods appear promising for identifying patients with low likelihood of PH.

Prognostic Significance of Elevated Left Ventricular Filling Pressures with Exercise: Insights from a Cohort of 14,338 Patients.

BACKGROUND: Exercise echocardiography can assess for cardiovascular causes of dyspnea other than coronary artery disease. However, the prevalence and prognostic significance of elevated left ventricular (LV) filling pressures with exercise is understudied. METHODS: We evaluated 14,338 patients referred for maximal symptom-limited treadmill echocardiography. In addition to assessment of LV regional wall motion abnormalities (RWMAs), we measured patients' early diastolic mitral inflow (E), septal mitral annulus relaxation (e'), and peak tricuspid regurgitation velocity before and immediately after exercise. RESULTS: Over a mean follow-up of 3.3 ± 3.4 years, patients with E/e' ≥15 with exercise (n = 1,323; 9.2%) had lower exercise capacity (7.3 ± 2.1 vs 9.1 ± 2.4 metabolic equivalents, P < .0001) and were more likely to have resting or inducible RWMAs (38% vs 18%, P < .0001). Approximately 6% (n = 837) had elevated LV filling pressures without RWMAs. Patients with a poststress E/e' ≥15 had a 2.71-fold increased mortality rate (2.28-3.21, P < .0001) compared with those with poststress E/e' ≤ 8. Those with an E/e' of 9 to 14, while at lower risk than the E/e' ≥15 cohort (hazard ratio [HR] = 0.58 [0.48-0.69]; P < .0001), had higher risk than if E/e' ≤8 (HR = 1.56 [1.37-1.78], P < .0001). On multivariable analysis, adjusting for age, sex, exercise capacity, LV ejection fraction, and presence of pulmonary hypertension with stress, patients with E/e' ≥15 had a 1.39-fold (95% CI, 1.18-1.65, P < .0001) increased risk of all-cause mortality compared with patients without elevated LV filling pressures. Compared with patients with E/e' ≤ 15 after exercise, patients with E/e' ≤15 at rest but elevated after exercise had a higher risk of cardiovascular death (HR = 8.99 [4.7-17.3], P < .0001). CONCLUSION: Patients with elevated LV filling pressures are at increased risk of death, irrespective of myocardial ischemia or LV systolic dysfunction. These findings support the routine incorporation of LV filling pressure assessment, both before and immediately following stress, into the evaluation of patients referred for exercise echocardiography.

Machine learning facilitates the prediction of long-term mortality in patients with tricuspid regurgitation.

OBJECTIVE: Tricuspid regurgitation (TR) is a prevalent valve disease associated with significant morbidity and mortality. We aimed to apply machine learning (ML) to assess risk stratification in patients with ≥moderate TR. METHODS: Patients with ≥moderate TR on echocardiogram between January 2005 and December 2016 were retrospectively included. We used 70% of data to train ML-based survival models including 27 clinical and echocardiographic features to predict mortality over a 3-year period on an independent test set (30%). To account for differences in baseline comorbidities, prediction was performed in groups stratified by increasing Charlson Comorbidity Index (CCI). Permutation feature importance was calculated using the best-performing model separately in these groups. RESULTS: Of 13 312 patients, mean age 72 ± 13 years and 7406 (55%) women, 7409 (56%) had moderate, 2646 (20%) had moderate-severe and 3257 (24%) had severe TR. The overall performance for 1-year mortality by 3 ML models was good, c-statistic 0.74-0.75. Interestingly, performance varied between CCI groups, (c-statistic = 0.774 in lowest CCI group and 0.661 in highest CCI group). The performance decreased over 3-year follow-up (average c-index 0.78). Furthermore, the top 10 features contributing to these predictions varied slightly with the CCI group, the top features included heart rate, right ventricular systolic pressure, blood pressure, diuretic use and age. CONCLUSIONS: Machine learning of common clinical and echocardiographic features can evaluate mortality risk in patients with TR. Further refinement of models and validation in prospective studies are needed before incorporation into the clinical practice.

Diastology with Cardiac MRI: A Practical Guide.

Diastolic filling of the ventricle is a complex interplay of volume and pressure, contingent on active energy-dependent myocardial relaxation and myocardial stiffness. Abnormal diastolic function is the hallmark of the clinical entity of heart failure with preserved ejection fraction (HFpEF), which is now the dominant type of heart failure and is associated with significant morbidity and mortality. Although echocardiography is the current first-line imaging modality used in evaluation of diastolic function, cardiac MRI (CMR) is emerging as an important technique. The principal role of CMR is to categorize the cause of diastolic dysfunction (DD) and distinguish other entities that manifest similarly to HFpEF, particularly infiltrative and pericardial disorders. CMR also provides prognostic information and risk stratification based on late gadolinium enhancement and parametric mapping techniques. Advances in hardware, sequences, and postprocessing software now enable CMR to diagnose and grade DD accurately, a role traditionally assigned to echocardiography. Two-dimensional or four-dimensional velocity-encoded phase-contrast sequences can measure flow and velocities at the mitral inflow, mitral annulus, and pulmonary veins to provide diastolic functional metrics analogous to those at echocardiography. The commonly used cine steady-state free-precession sequence can provide clues to DD including left ventricular mass, left ventricular filling curves, and left atrial size and function. MR strain imaging provides information on myocardial mechanics that further aids in diagnosis and prognosis of diastolic function. Research sequences such as MR elastography and MR spectroscopy can help evaluate myocardial stiffness and metabolism, respectively, providing additional insights on diastolic function. The authors review the physiology of diastolic function, mechanics of diastolic heart failure, and CMR techniques in the evaluation of diastolic function. ©RSNA, 2023 Quiz questions for this article are available in the supplemental material.

Cardiac Masses Discovered by Echocardiogram; What to Do Next?

Cardiac tumors are rare conditions, typically diagnosed on autopsy, but with the advancement of imaging techniques they are now encountered more frequently in clinical practice. Echocardiography is often the initial method of investigation for cardiac masses and provides a quick and valuable springboard for their characterization. While some cardiac masses can be readily identified by echocardiography alone, several require incorporation of multiple data points to reach diagnostic certainty. Herein, we will provide an overview of the main clinical, diagnostic, and therapeutic characteristics of cardiac masses within the framework of their location.

Analysis of Cardiac Computed Tomography Anatomy in Patients With Severe Tricuspid Regurgitation Considered for Transcatheter Intervention.

Background: Severe tricuspid regurgitation (TR) is associated with considerable morbidity/mortality in an elderly population with multiple comorbidities. There is interest in transcatheter interventions to manage severe TR. Understanding complex right heart (RH) geometry and tricuspid valve shape and size has implications for patient/device selection for transcatheter intervention. We characterized RH anatomy by computed tomography in patients with symptomatic severe TR considered for intervention. Methods: The retrospective Mayo Clinic study included 29 patients with an echocardiogram and cardiac computed tomography angiogram considered for intervention of severe TR from March 01, 2016 to December 15, 2020. Patients were divided into 2 groups: intervention (surgical or transcatheter; n = 17) and medical management alone (n = 12). Results: Mean age was 83 ± 8 (83% female), 100% had atrial fibrillation, and 62% had chronic kidney disease ≥3a. Ninety-seven percent were symptomatic, 93% had been prescribed loop diuretics, and 24% had device leads. Mean tricuspid annular plane systolic excursion was 16.8 ± 4.5 mm, effective regurgitant orifice area was 81 ± 33 mm2, and cardiac index was 2.6 ± 0.6 L/min/m2. Forty-one percent had at least moderate right ventricular (RV) dysfunction with a mean RV systolic pressure of 46 ± 16 mmHg. Patients receiving intervention had significantly larger effective regurgitant orifice area (101 ± 33 vs. 63 ± 22 mm2, p = 0.033), shorter tricuspid leaflet tenting length (6.5 ± 3.0 vs. 8.9 ± 2.7 mm, p = 0.042), and smaller annuloplasty diagnostic perimeter during diastole (120.1 ± 16.6 vs. 131.1 ± 7.4 mm, p = 0.041). Intervention patients tended to have better right ventricular function, smaller RV and inferior vena cava size, and more severe symptoms. The maximal tricuspid annulus diameter in systole and diastole was 51 ± 5 and 53 ± 7 mm, respectively. Conclusions: Severe TR patients referred for transcatheter intervention present with severe RH enlargement with a large proportion having tricuspid annulus dimensions outside the range for current devices available in clinical trials. The presented data have implications for device development/selection and procedural feasibility.

Machine learning-based risk stratification for mortality in patients with severe aortic regurgitation.

Aims: The current guidelines recommend aortic valve intervention in patients with severe aortic regurgitation (AR) with the onset of symptoms, left ventricular enlargement, or systolic dysfunction. Recent studies have suggested that we might be missing the window of early intervention in a significant number of patients by following the guidelines. Methods and results: The overarching goal was to determine if machine learning (ML)-based algorithms could be trained to identify patients at risk for death from AR independent of aortic valve replacement (AVR). Models were trained with five-fold cross-validation on a dataset of 1035 patients, and performance was reported on an independent dataset of 207 patients. Optimal predictive performance was observed with a conditional random survival forest model. A subset of 19/41 variables was selected for inclusion in the final model. Variable selection was performed with 10-fold cross-validation using random survival forest model. The top variables included were age, body surface area, body mass index, diastolic blood pressure, New York Heart Association class, AVR, comorbidities, ejection fraction, end-diastolic volume, and end-systolic dimension, and the relative variable importance averaged across five splits of cross-validation in each repeat were evaluated. The concordance index for predicting survival of the best-performing model was 0.84 at 1 year, 0.86 at 2 years, and 0.87 overall, respectively. Conclusion: Using common echocardiographic parameters and patient characteristics, we successfully trained multiple ML models to predict survival in patients with severe AR. This technique could be applied to identify high-risk patients who would benefit from early intervention, thereby improving patient outcomes.

The 5 Phenotypes of Tricuspid Regurgitation: Insight From Cluster Analysis of Clinical and Echocardiographic Variables.

BACKGROUND: The recent morphologic classification of tricuspid regurgitation (TR) (ie, atrial functional, ventricular functional, lead related, and primary) does not capture underlying comorbidities and clinical characteristics. OBJECTIVES: This study aimed to identify the different phenotypes of TR using unsupervised cluster analysis and to determine whether differences in clinical outcomes were associated with these phenotypes. METHODS: We included 13,611 patients with ≥moderate TR from January 2004 to April 2019 in the final analyses. Baseline demographic, clinical, and echocardiographic data were obtained from electronic medical records and echocardiography reports. Ward's minimum variance method was used to cluster patients based on 38 variables. The analysis of all-cause mortality was performed using the Kaplan-Meier method, and groups were compared using log-rank test. RESULTS: The mean age of patients was 72 ± 13 years, and 56% were women. Cluster analysis identified 5 distinct phenotypes: cluster 1 represented "low-risk TR" with less severe TR, a lower prevalence of right ventricular enlargement, atrial fibrillation, and comorbidities; cluster 2 represented "high-risk TR"; and clusters 3, 4, and 5 represented TR associated with lung disease, coronary artery disease, and chronic kidney disease, respectively. Cluster 1 had the lowest mortality followed by clusters 2 (HR: 2.22 [95% CI: 2.1-2.35]; P < 0.0001) and 4 (HR: 2.19 [95% CI: 2.04-2.35]; P < 0.0001); cluster 3 (HR: 2.45 [95% CI: 2.27-2.65]; P < 0.0001); and, lastly, cluster 5 (HR: 3.48 [95% CI: 3.07-3.95]; P < 0.0001). CONCLUSIONS: Cluster analysis identified 5 distinct novel subgroups of TR with differences in all-cause mortality. This phenotype-based classification improves our understanding of the interaction of comorbidities with this complex valve lesion and can inform clinical decision making.

Right ventricular systolic strain in patients with pulmonary hypertension: clinical feasibility, reproducibility, and correlation with ejection fraction.

BACKGROUND: Right ventricular (RV) systolic function is the major determinant of prognosis in patients with pulmonary hypertension (PH) with quantitative assessment by speckle-tracking strain echocardiography emerging as a viable candidate measure. METHOD: We evaluated a prospective cohort of 231 patients with known or suspected PH referred for clinical echocardiography. All underwent measurement of RV free-wall systolic strain by sonographer staff. Digital images were recorded for blinded offline assessment by an expert echocardiographer. Reproducibility was assessed using the analysis methods of Bland-Altman and the Cohen's-Kappa coefficient. RESULTS: RV strain was feasible in 213 (92%). The average RV systolic pressure was 59 ± 22 mmHg. RV systolic strain correlated with functional class, NT-proBNP, and the degree of RV enlargement. The average free-wall systolic strain was - 20 ± 7% (range - 2 to - 37%). The RV strain measures (clinical practice versus blinded expert) had an excellent correlation with a normal distribution (R2 0.87, p < 0.0001). By Bland-Altman analysis, the mean difference in measurement was - 1.7% (95% CI - 1.4 to - 2.1) with a correlation of 0.93, p value of < 0.0001. The reproducibility of RV strain for clinically relevant thresholds was also excellent (Kappa coefficients 0.68-0.83). There was no effect on the variability of strain measures across body mass, pulmonary pressures, or rhythm. RV strain correlated with RV diastolic volumes and ejection fraction with RV free wall strain being the best echo predictor for a reduction in ejection fraction. CONCLUSION: Here RV systolic strain was found to be highly feasible and reproducible in clinical practice with excellent levels of agreement for clinically relevant thresholds.

Prevalence, sex differences, and implications of pulmonary hypertension in patients with apical hypertrophic cardiomyopathy.

Introduction: Apical hypertrophic cardiomyopathy (ApHCM) is a subtype of hypertrophic cardiomyopathy (HCM) that affects up to 25% of Asian patients and is not as well understood in non-Asian patients. Although ApHCM has been considered a more "benign" variant, it is associated with increased risk of atrial and ventricular arrhythmias, apical thrombi, stroke, and progressive heart failure. The occurrence of pulmonary hypertension (PH) in ApHCM, due to elevated pressures on the left side of the heart, has been documented. However, the exact prevalence of PH in ApHCM and sex differences remain uncertain. Methods: We sought to evaluate the prevalence, risk associations, and sex differences in elevated pulmonary pressures in the largest cohort of patients with ApHCM at a single tertiary center. A total of 542 patients diagnosed with ApHCM were identified using ICD codes and clinical notes searches, confirmed by cross-referencing with cardiac MRI reports extracted through Natural Language Processing and through manual evaluation of patient charts and imaging records. Results: In 414 patients, echocardiogram measurements of pulmonary artery systolic pressure (PASP) were obtained at the time of diagnosis. The mean age was 59.4 ± 16.6 years, with 181 (44%) being females. The mean PASP was 38 ± 12 mmHg in females vs. 33 ± 9 mmHg in males (p < 0.0001). PH as defined by a PASP value of > 36 mmHg was present in 140/414 (34%) patients, with a predominance in females [79/181 (44%)] vs. males [61/233 (26%), p < 0.0001]. Female sex, atrial fibrillation, diagnosis of congestive heart failure, and elevated filling pressures on echocardiogram remained significantly associated with PH (PASP > 36 mmHg) in multivariable modeling. PH, when present, was independently associated with mortality [hazard ratio 1.63, 95% CI (1.05-2.53), p = 0.028] and symptoms [odds ratio 2.28 (1.40, 3.71), p < 0.001]. Conclusion: PH was present in 34% of patients with ApHCM at diagnosis, with female sex predominance. PH in ApHCM was associated with symptoms and increased mortality.

The feasibility and value of assessing patient-reported outcomes in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a progressive pulmonary vascular disease that negatively impacts health-related quality of life (HRQOL). The PAH-symptoms and impact (PAH-SYMPACT) questionnaire is a validated disease-specific patient-reported outcome (PRO) instrument that assesses a patient's symptoms and the impact of PAH and its treatment on well-being. We performed a single-center prospective cohort study of patients with PAH to determine the feasibility of assessing PROs in clinical practice and to determine the association between PAH-SYMPACT domains and clinical characteristics and outcomes. One hundred and ten patients completed the 1-day version of the PAH-SYMPACT questionnaire which consists of 22 Likert-scale questions that assess HRQOL across four domains: cardiopulmonary (CP) symptoms, cardiovascular (CV) symptoms, physical impact (PI), and cognitive and emotional (CE) impact. Higher scores indicate worse HRQOL. Patients were predominantly female (n = 86, 78%) with a mean age of 57.8 ± 16.2 years. While several patient characteristics were associated with CP and PI domains, few were associated with CV and CE domains. PI and CE impact scores were associated with recent hospitalizations and mortality and CE impact score was independently associated with an increased risk of death after adjustment for disease severity (hazard ratio: 3.29, 95% confidence interval: 1.56-6.91, p = 0.002). In conclusion, the assessment of PROs in clinical practice using the PAH-SYMPACT questionnaire is both feasible and valuable. PAH-SYMPACT scores have independent prognostic value and are not adequately reflected by traditional measures of disease severity. These findings underscore the importance of assessing HRQOL in clinical practice.

Clinical Impact of Cardiac Fibromas.

Cardiac fibromas are rare primary tumors that can cause significant morbidity and mortality. There has not been a large clinical case review since 1994. This study provides an updated analysis of clinical impact, thereby enhancing understanding, increasing awareness, and revealing important factors in the diagnosis and management of cardiac fibromas. A retrospective case series was conducted at a tertiary care institution by reviewing radiology, surgical and pathology archives (1964 to 2020). Cases were included if cardiac fibroma was diagnosed through imaging or pathology. Demographics, symptomatology, electrophysiologic data, radiographic findings, pathology, interventions, and outcomes were examined. A total of 26 patients with cardiac fibromas were identified, including 12 women. The median age was 20.5 years (0 days to 72 years). Symptoms included palpitations (commonly due to ventricular tachycardia, 31%), syncope (15%), angina (15%), heart failure (12%), emboli (4%), and murmur (27%). One patient had Gorlin syndrome. A total of 22 patients were diagnosed through imaging, 15 of whom were biopsy-confirmed. A total of 9 patients were initially observed. A total of 2 eventually had surgery, 1 was lost to follow-up, 3 were asymptomatic, 1 had heart failure and atrial fibrillation, and 1 had atrial fibrillation and tachy-brady syndrome, requiring ablation and pacemaker placement. A total of 19 underwent resection. A total of 4 required complex operations, 1 required a second resection, and 1 operative death occurred. In conclusion, cardiac fibromas primarily affect the pediatric population; however, this study demonstrates a significant prevalence in adults. Ventricular tachycardia is common, and multimodality imaging is diagnostically sensitive. Resection is largely successful in symptomatic patients. Surveillance may be appropriate for asymptomatic patients.

Prognostic Role of Cardiac Power in a Large Cohort of Patients with Normal Ejection Fraction Referred for Dobutamine Stress Echocardiography.

BACKGROUND: Cardiac power reflects cardiac performance in terms of energy transferred by the left ventricle to the aorta per unit time. Peak stress cardiac power has been shown to predict outcomes in patients with reduced left ventricular ejection fraction (LVEF) and, more recently, in patients with normal LVEF referred for exercise stress echocardiography. The aim of this study was to evaluate the prognostic significance of cardiac power in patients with normal LVEF referred for dobutamine stress echocardiography. METHODS: Data were studied from 15,576 patients with LVEF ≥ 50% and no significant valvular or right ventricular dysfunction who underwent dobutamine stress echocardiography. Cardiac power at rest and peak stress and power reserve (peak stress minus rest power) were calculated and normalized to left ventricular mass. Outcome end points were all-cause mortality and new-onset heart failure (HF). RESULTS: The mean age was 66 ± 13 years, and 49% patients were women. Resting and peak stress power/mass were 0.7 ± 0.2 and 1.6 ± 0.6 W/100 g left ventricular myocardium, respectively. During follow-up (median, 3.3 years; interquartile range, 0.7-7.3 years), 2,278 patients died and 2,137 developed HF. After adjusting for age, sex, comorbidities, and stress test results, lower peak stress power/mass was independently associated with mortality (adjusted hazard ratio, highest vs lowest quartile, 0.84; 95% CI, 0.74-0.95; P = .004) and HF at follow-up (adjusted hazard ratio, 0.67; 95% CI, 0.59-0.76; P < .0001). Power reserve showed similar associations with outcomes. CONCLUSIONS: Assessment of cardiac power during dobutamine stress echocardiography in patients with normal LVEF provides valuable prognostic information regarding risk for mortality and future HF, in addition to stress test results. It is an important research tool to study cardiac performance, and the development of risk scores incorporating this novel index could be considered after further validation in prospective studies.