Prognostic Value of Magnetic Resonance Phenotype in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy

BackgroundCardiac magnetic resonance (CMR) is widely used to assess tissue and functional abnormalities in arrhythmogenic right ventricular cardiomyopathy (ARVC). Recently, a ARVC risk score was proposed to predict the 5-year risk of malignant ventricular arrhythmias in patients with ARVC. However, CMR features such as fibrosis, fat infiltration, and left ventricular (LV) involvement were not considered.ObjectivesThe authors sought to evaluate the prognostic role of CMR phenotype in patients with definite ARVC and to evaluate the effectiveness of the novel 5-year ARVC risk score to predict cardiac events in different CMR presentations.MethodsA total of 140 patients with definite ARVC were enrolled (mean age 42 ± 17 years, 97 males) in this multicenter prospective registry. As per study design, CMR was performed in all the patients at enrollment. The novel 5-year ARVC risk score was retrospectively calculated using the patient’s characteristics at the time of enrollment. During a median follow-up of 5 years (2 to 8 years), the combined endpoint of sudden cardiac death, appropriate implantable cardioverter-defibrillator intervention, and aborted cardiac arrest was considered.ResultsCMR was completely negative in 14 patients (10%), isolated right ventricular (RV) involvement was found in 58 (41%), biventricular in 52 (37%), and LV dominant in 16 (12%). During the follow-up, 48 patients (34%) had major events, but none occurred in patients with negative CMR. At Kaplan-Meier analysis, patients with LV involvement (LV dominant and biventricular) had a worse prognosis than those with lone RV (p < 0.0001). At multivariate analysis, the LV involvement, a LV-dominant phenotype, and the 5-year ARVC risk score were independent predictors of major events. The estimated 5-year risk was able to predict the observed risk in patients with lone RV but underestimated the risk in those with LV involvement.ConclusionsDifferent CMR presentations of ARVC are associated with different prognoses. The 5-year ARVC risk score is valid for the estimation of risk in patients with lone-RV presentation but underestimated the risk when LV is involved.     

Improved Risk Stratification for Ventricular Arrhythmias and Sudden Death in Patients With Nonischemic Dilated Cardiomyopathy

BackgroundRisk stratification for ventricular arrhythmias (VA) and sudden death in nonischemic dilated cardiomyopathy (DCM) remains suboptimal.ObjectivesThe goal of this study was to provide an improved risk stratification algorithm for VA and sudden death in DCM.MethodsThis was a retrospective cohort study of consecutive patients with DCM who underwent cardiac magnetic resonance with late gadolinium enhancement (LGE) at 2 tertiary referral centers. The combined arrhythmic endpoint included appropriate implantable cardioverter-defibrillator therapies, sustained ventricular tachycardia, resuscitated cardiac arrest, and sudden death.ResultsIn 1,165 patients with a median follow-up of 36 months, LGE was an independent and strong predictor of the arrhythmic endpoint (hazard ratio: 9.7; p < 0.001). This association was consistent across all strata of left ventricular ejection fraction (LVEF). Epicardial LGE, transmural LGE, and combined septal and free-wall LGE were all associated with heightened risk. A simple algorithm combining LGE and 3 LVEF strata (i.e., ≤20%, 21% to 35%, >35%) was significantly superior to LVEF with the 35% cutoff (Harrell’s C statistic: 0.8 vs. 0.69; area under the curve: 0.82 vs. 0.7; p < 0.001) and reclassified the arrhythmic risk of 34% of patients with DCM. LGE-negative patients with LVEF 21% to 35% had low risk (annual event rate 0.7%), whereas those with high-risk LGE distributions and LVEF >35% had significantly higher risk (annual event rate 3%; p = 0.007).ConclusionsIn a large cohort of patients with DCM, LGE was found to be a significant, consistent, and strong predictor of VA or sudden death. Specific high-risk LGE distributions were identified. A new clinical algorithm integrating LGE and LVEF significantly improved the risk stratification for VA and sudden death, with relevant implications for implantable cardioverter-defibrillator allocation.     

Clinical Characteristics and Prognostic Importance of Left Ventricular Apical Aneurysms in Hypertrophic Cardiomyopathy

BackgroundLeft ventricular (LV) apical aneurysms in hypertrophic cardiomyopathy (HCM) are a recognized risk marker for adverse cardiovascular events. There is variable practice among clinicians and discordance between international guidelines regarding treatment recommendations and prognostication for this important phenotype.ObjectivesThe authors sought to describe the morphology, clinical course, and risk of adverse events in a large single-center cohort of HCM patients with LV apical aneurysms.MethodsThis study analyzed 160 HCM patients with an LV apical aneurysm who were evaluated in our dedicated HCM clinic between January 1997 and April 2021.ResultsMean age was 59.1 ± 13.6 years, and 71% of these patients were male. Mean aneurysm size was 1.77 ± 1.04 cm. Over 6.2 ± 4.8 years, 14 (9%) patients had a sudden cardiac death (SCD) event, including appropriate therapy from an implantable cardioverter-defibrillator (ICD) or resuscitation from cardiac arrest (annualized event rate 1.77%/y), 39 (24%) had either a thromboembolic stroke or apical thrombus formation (2.9%/y), and 14 (9%) developed LV systolic dysfunction with an ejection fraction (EF) <50% (1.28%/y). HRs for SCD, stroke or thrombus, and EF <50% per 1-cm increase in aneurysm size were 1.69 (P = 0.007), 1.60 (P = 0.0002), and 1.63 (P = 0.01), respectively. Aneurysm size ≥2 cm was associated with a 5-year SCD rate of 9.7%, compared with 2.9% for aneurysm size <2 cm (log-rank P = 0.037). This subgroup also had higher risk of stroke/thrombus formation (HR: 2.20; P = 0.002), with an annualized event rate of 2.7%/year. A total of 39 (24%) patients reached the combined end point of SCD, stroke, or LV dysfunction (2.12%/y) with an HR of 1.47/cm increase in aneurysm size (P = 0.003) and an HR of 2.22 for patients with aneurysm size ≥2 cm (P = 0.02).ConclusionsIncreasing aneurysm size confers poorer prognosis. Aneurysm size ≥2 cm should alert potential consideration for prophylactic anticoagulation and primary prevention ICDs.     

Outcomes in Patients With Hypertrophic Cardiomyopathy and Left Ventricular Systolic Dysfunction

BackgroundEnd-stage (ES) hypertrophic cardiomyopathy (HCM) has been considered a particularly grim and unfavorable disease complication, associated with substantial morbidity and mortality, frequently requiring heart transplant. Previous reports have included small numbers of patients with relatively short follow-up, predominantly in prior treatment eras.ObjectivesThe purpose of this study was to re-evaluate clinical profile and prognosis for end-stage heart failure in a large HCM cohort with contemporary management strategies.MethodsPatients at Tufts HCM Institute, from 2004 to 2017, were identified with ES and systolic dysfunction (ejection fraction [EF] <50%), followed for 5.8 ± 4.7 years (up to 18 years).ResultsOf the 2,447 patients, 118 (4.8%) had ES-HCM (EF 39 ± 9%; range 12% to 49%) at age 48 ± 15 years. Notably, over follow-up, 57 patients (48%) achieved clinical stability in New York Heart Association functional classes I/II with medical treatment (or cardiac resynchronization therapy), including 6 patients ≥10 years from ES diagnosis (up to 14 years). In total, 61 other patients (52%) developed refractory heart failure to disabling New York Heart Association functional classes III/IV (5.2%/year); 67% have survived, including 31 with heart transplant. Of the 118 ES patients, 21 had appropriate implantable cardioverter-defibrillator (ICD) therapy terminating potentially lethal tachyarrhythmias, with no difference in frequency of events in patients with EF 35% to 49% versus EF <35% (17% vs. 19%; p = 0.80). With all available treatment modalities, ES-related mortality was 1.9%/year, with 10-year survival of 85% (95% confidence interval: 77% to 94%). Mortality was 4-fold lower than previously reported for ES (8.0%/year), but exceeded 10-fold HCM with preserved EF (0.2%/year; p < 0.001).ConclusionsAlthough ES remains an important complication of HCM, contemporary treatment strategies, including ICDs and heart transplant, are associated with significantly lower mortality than previously considered. Primary prevention ICDs should be considered when EF is <50% in HCM. Rapid heart failure progression is not an inevitable consequence of ES, and some patients experience extended periods of clinical stability.     

Right Ventricular Functional Abnormalities in Arrhythmogenic Cardiomyopathy: Association With Life-Threatening Ventricular Arrhythmias

ObjectivesThis study aimed to perform an external validation of the value of right ventricular (RV) deformation patterns and RV mechanical dispersion in patients with arrhythmogenic cardiomyopathy (AC). Secondly, this study assessed the association of these parameters with life-threatening ventricular arrhythmia (VA).BackgroundSubtle RV dysfunction assessed by echocardiographic deformation imaging is valuable in AC diagnosis and risk prediction. Two different methods have emerged, the RV deformation pattern recognition and RV mechanical dispersion, but these have neither been externally validated nor compared.MethodsWe analyzed AC probands and mutation-positive family members, matched from 2 large European referral centers. We performed speckle tracking echocardiography, whereby we classified the subtricuspid deformation patterns from normal to abnormal and assessed RV mechanical dispersion from 6 segments. We defined VA as sustained ventricular tachycardia, appropriate implantable cardioverter-defibrillator therapy, or aborted cardiac arrest.ResultsWe included 160 subjects, 80 from each center (43% proband, 55% women, age 41 ± 17 years). VA had occurred in 47 (29%) subjects. In both cohorts, patients with a history of VA showed abnormal deformation patterns (96% and 100%) and had greater RV mechanical dispersion (53 ± 30 ms vs. 30 ± 21 ms; p < 0.001 for the total cohort). Both parameters were independently associated to VA (adjusted odds ratio: 2.71 [95% confidence interval: 1.47 to 5.00] per class step-up, and 1.26 [95% confidence interval: 1.07 to 1.49]/10 ms, respectively). The association with VA significantly improved when adding RV mechanical dispersion to pattern recognition (net reclassification improvement 0.42; p = 0.02 and integrated diagnostic improvement 0.06; p = 0.01).ConclusionsWe externally validated 2 RV dysfunction parameters in AC. Adding RV mechanical dispersion to RV deformation patterns significantly improved the association with life-threatening VA, indicating incremental value.     

Prognostic Value of Right Ventricular Function in Patients With Suspected Myocarditis Undergoing Cardiac Magnetic Resonance

BackgroundRisk-stratification of myocarditis is based on functional parameters and tissue characterization of the left ventricle (LV), whereas right ventricular (RV) involvement remains mostly unrecognized.ObjectivesIn this study, the authors sought to analyze the prognostic value of RV involvement in myocarditis by cardiac magnetic resonance (CMR).MethodsPatients meeting the recommended clinical criteria for suspected myocarditis were enrolled at 2 centers. Exclusion criteria were the evidence of coronary artery disease, pulmonary artery hypertension or structural cardiomyopathy. Biventricular ejection fraction, edema according to T2-weighted images, and late gadolinium enhancement (LGE) were linked to a composite end point of major adverse cardiovascular events (MACE), including heart failure hospitalization, ventricular arrhythmia, recurrent myocarditis, and death.ResultsAmong 1,125 consecutive patients, 736 (mean age: 47.8 ± 16.1 years) met the clinical diagnosis of suspected myocarditis and were followed for 3.7 years. Signs of RV involvement (abnormal right ventricular ejection fraction [RVEF], RV edema, and RV-LGE) were present in 188 (25.6%), 158 (21.5%), and 92 (12.5%) patients, respectively. MACE occurred in 122 patients (16.6%) and was univariably associated with left ventricular ejection fraction (LVEF), LV edema, LV-LGE, RV-LGE, RV edema, and RVEF. In a series of nesting multivariable Cox regression models, the addition of RVEF (HR_adj: 0.974 [95% CI: 0.956-0.993]; P = 0.006) improved prognostication (chi-square test = 89.5; P = 0.001 vs model 1; P = 0.006 vs model 2) compared with model 1 including only clinical variables (chi-square test = 28.54) and model 2 based on clinical parameters, LVEF, and LV-LGE extent (chi-square test = 78.93).ConclusionsThis study emphasizes the role of RV involvement in myocarditis and demonstrates the independent and incremental prognostic value of RVEF beyond clinical variables, CMR tissue characterization, and LV function. (Inflammatory Cardiomyopathy Bern Registry [FlamBER]; NCT04774549; CMR Features in Patients With Suspected Myocarditis [CMRMyo]; NCT03470571)     

Prognostic Significance of Nonischemic Myocardial Fibrosis in Patients With Normal LV Volumes and Ejection-Fraction

ObjectivesThis study aims to investigate the prognostic significance of late gadolinium enhancement (LGE) in patients without coronary artery disease and with normal range left ventricular (LV) volumes and ejection fraction.BackgroundNonischemic patterns of LGE with normal LV volumes and ejection fraction are increasingly detected on cardiovascular magnetic resonance, but their prognostic significance, and consequently management, is uncertain.MethodsPatients with midwall/subepicardial LGE and normal LV volumes, wall thickness, and ejection fraction on cardiovascular magnetic resonance were enrolled and compared to a control group without LGE. The primary outcome was actual or aborted sudden cardiac death (SCD).ResultsOf 748 patients enrolled, 401 had LGE and 347 did not. The median age was 50 years (interquartile range: 38-61 years), LV ejection fraction 66% (interquartile range: 62%-70%), and 287 (38%) were women. Scan indications included chest pain (40%), palpitation (33%) and breathlessness (13%). No patient experienced SCD and only 1 LGE+ patient (0.13%) had an aborted SCD in the 11th follow-up year. Over a median of 4.3 years, 30 patients (4.0%) died. All-cause mortality was similar for LGE+/- patients (3.7% vs 4.3%; P = 0.71) and was associated with age (HR: 2.04 per 10 years; 95% CI: 1.46-2.79; P < 0.001). Twenty-one LGE+ and 4 LGE- patients had an unplanned cardiovascular hospital admission (HR: 7.22; 95% CI: 4.26-21.17; P < 0.0001).ConclusionsThere was a low SCD risk during long-term follow-up in patients with LGE but otherwise normal LV volumes and ejection fraction. Mortality was driven by age and not LGE presence, location, or extent, although the latter was associated with greater cardiovascular hospitalization for suspected myocarditis and symptomatic ventricular tachycardia.     

Prognostic Value of Right Ventricular Longitudinal Strain in Patients With COVID-19

ObjectivesThe aim of this study was to investigate whether right ventricular longitudinal strain (RVLS) was independently predictive of higher mortality in patients with coronavirus disease-2019 (COVID-19).BackgroundRVLS obtained from 2-dimensional speckle-tracking echocardiography has been recently demonstrated to be a more accurate and sensitive tool to estimate right ventricular (RV) function. The prognostic value of RVLS in patients with COVID-19 remains unknown.MethodsOne hundred twenty consecutive patients with COVID-19 who underwent echocardiographic examinations were enrolled in our study. Conventional RV functional parameters, including RV fractional area change, tricuspid annular plane systolic excursion, and tricuspid tissue Doppler annular velocity, were obtained. RVLS was determined using 2-dimensional speckle-tracking echocardiography. RV function was categorized in tertiles of RVLS.ResultsCompared with patients in the highest RVLS tertile, those in the lowest tertile were more likely to have higher heart rate; elevated levels of D-dimer and C-reactive protein; more high-flow oxygen and invasive mechanical ventilation therapy; higher incidence of acute heart injury, acute respiratory distress syndrome, and deep vein thrombosis; and higher mortality. After a median follow-up period of 51 days, 18 patients died. Compared with survivors, nonsurvivors displayed enlarged right heart chambers, diminished RV function, and elevated pulmonary artery systolic pressure. Male sex, acute respiratory distress syndrome, RVLS, RV fractional area change, and tricuspid annular plane systolic excursion were significant univariate predictors of higher risk for mortality (p < 0.05 for all). A Cox model using RVLS (hazard ratio: 1.33; 95% confidence interval [CI]: 1.15 to 1.53; p < 0.001; Akaike information criterion = 129; C-index = 0.89) was found to predict higher mortality more accurately than a model with RV fractional area change (Akaike information criterion = 142, C-index = 0.84) and tricuspid annular plane systolic excursion (Akaike information criterion = 144, C-index = 0.83). The best cutoff value of RVLS for prediction of outcome was −23% (AUC: 0.87; p < 0.001; sensitivity, 94.4%; specificity, 64.7%).ConclusionsRVLS is a powerful predictor of higher mortality in patients with COVID-19. These results support the application of RVLS to identify higher risk patients with COVID-19.     

Prevalence and Prognostic Significance of Microvascular Dysfunction in Heart Failure With Preserved Ejection Fraction

BackgroundThe pathophysiological and clinical significance of microvascular dysfunction (MVD) in patients with heart failure with preserved ejection fraction (HFpEF) remains uncertain.ObjectivesThe aim of this study was to use cardiovascular magnetic resonance to: 1) quantify coronary microvascular function; 2) examine the relationship between perfusion and fibrosis; and 3) evaluate the impact of MVD and fibrosis on long-term clinical outcomes.MethodsIn a prospective, observational study, patients with HFpEF and control subjects underwent multiparametric cardiovascular magnetic resonance (comprising assessment of left ventricular volumetry, perfusion, and fibrosis [focal by late gadolinium enhancement and diffuse by extracellular volume]). The primary endpoint was the composite of death or hospitalization with heart failure.ResultsOne hundred and one patients with HFpEF (mean age 73 ± 9 years, mean ejection fraction 56% ± 5%) and 43 control subjects (mean age 73 ± 5 years, mean ejection fraction 58% ± 5%) were studied. Myocardial perfusion reserve (MPR) was lower in patients with HFpEF versus control subjects (1.74 ± 0.76 vs 2.22 ± 0.76; P = 0.001). MVD (defined as MPR <2.0) was present in 70% of patients with HFpEF (vs 48% of control subjects; P = 0.014). There was no significant linear correlation between MPR and diffuse fibrosis (r = ?0.10; P = 0.473) and no difference in MPR between those with and without focal fibrosis (mean difference ?0.03; 95% CI: ?0.37 to 0.30). In the HFpEF group, during median follow-up of 3.1 years, there were 45 composite events. MPR was independently predictive of clinical outcome following adjustment for clinical, blood, and imaging parameters (1 SD increase: HR: 0.673 [95% CI: 0.463 to 0.978; P = 0.038]; HR: 0.694 [95% CI: 0.491 to 0.982; P = 0.039]; and HR: 0.690 [95% CI: 0.489 to 0.973; P = 0.034], respectively).ConclusionsMVD is highly prevalent among patients with HFpEF and is an independent predictor of prognosis. The lack of correlation between MVD and fibrosis may challenge the assertion of a direct causal link between these entities. (Developing Imaging and Plasma Biomarkers in Describing Heart Failure With Preserved Ejection Fraction [DIAMONDHFpEF]; NCT03050593)     

Using Deep-Learning Algorithms to Simultaneously Identify Right and Left Ventricular Dysfunction From the Electrocardiogram

ObjectivesThis study sought to develop DL models capable of comprehensively quantifying left and right ventricular dysfunction from ECG data in a large, diverse population.BackgroundRapid evaluation of left and right ventricular function using deep learning (DL) on electrocardiograms (ECGs) can assist diagnostic workflow. However, DL tools to estimate right ventricular (RV) function do not exist, whereas those to estimate left ventricular (LV) function are restricted to quantification of very low LV function only.MethodsA multicenter study was conducted with data from 5 New York City hospitals: 4 for internal testing and 1 serving as external validation. We created novel DL models to classify left ventricular ejection fraction (LVEF) into categories derived from the latest universal definition of heart failure, estimate LVEF through regression, and predict a composite outcome of either RV systolic dysfunction or RV dilation.ResultsWe obtained echocardiogram LVEF estimates for 147,636 patients paired to 715,890 ECGs. We used natural language processing (NLP) to extract RV size and systolic function information from 404,502 echocardiogram reports paired to 761,510 ECGs for 148,227 patients. For LVEF classification in internal testing, area under curve (AUC) at detection of LVEF ≤40%, 40% < LVEF ≤50%, and LVEF >50% was 0.94 (95% CI: 0.94-0.94), 0.82 (95% CI: 0.81-0.83), and 0.89 (95% CI: 0.89-0.89), respectively. For external validation, these results were 0.94 (95% CI: 0.94-0.95), 0.73 (95% CI: 0.72-0.74), and 0.87 (95% CI: 0.87-0.88). For regression, the mean absolute error was 5.84% (95% CI: 5.82%-5.85%) for internal testing and 6.14% (95% CI: 6.13%-6.16%) in external validation. For prediction of the composite RV outcome, AUC was 0.84 (95% CI: 0.84-0.84) in both internal testing and external validation.ConclusionsDL on ECG data can be used to create inexpensive screening, diagnostic, and predictive tools for both LV and RV dysfunction. Such tools may bridge the applicability of ECGs and echocardiography and enable prioritization of patients for further interventions for either sided failure progressing to biventricular disease.     

Left Atrial Strain Has Superior Prognostic Value to Ventricular Function and Delayed-Enhancement in Dilated Cardiomyopathy

BackgroundThe left atrium is an early sensor of left ventricular (LV) dysfunction. Still, the prognostic value of left atrial (LA) function (strain) on cardiac magnetic resonance (CMR) in dilated cardiomyopathy (DCM) remains unknown.ObjectivesThe goal of this study was to evaluate the prognostic value of CMR-derived LA strain in DCM.MethodsPatients with DCM from the Maastricht Cardiomyopathy Registry with available CMR imaging were included. The primary endpoint was the combination of sudden or cardiac death, heart failure (HF) hospitalization, or life-threatening arrhythmias. Given the nonlinearity of continuous variables, cubic spline analysis was performed to dichotomize.ResultsA total of 488 patients with DCM were included (median age: 54 [IQR: 46-62] years; 61% male). Seventy patients (14%) reached the primary endpoint (median follow-up: 6 [IQR: 4-9] years). Age, New York Heart Association (NYHA) functional class >II, presence of late gadolinium enhancement (LGE), LV ejection fraction (LVEF), LA volume index (LAVI), LV global longitudinal strain (GLS), and LA reservoir and conduit strain were univariably associated with the outcome (all P < 0.02). LA conduit strain was a stronger predictor of outcome compared with reservoir strain. LA conduit strain, NYHA functional class >II, and LGE remained associated in the multivariable model (LA conduit strain HR: 3.65 [95% CI: 2.01-6.64; P < 0.001]; NYHA functional class >II HR: 1.81 [95% CI: 1.05-3.12; P = 0.033]; and LGE HR: 2.33 [95% CI: 1.42-3.85; P < 0.001]), whereas age, N-terminal pro–B-type natriuretic peptide, LVEF, left atrial ejection fraction, LAVI, and LV GLS were not. Adding LA conduit strain to other independent predictors (NYHA functional class and LGE) significantly improved the calibration, accuracy, and reclassification of the prediction model (P < 0.05).ConclusionsLA conduit strain on CMR is a strong independent prognostic predictor in DCM, superior to LV GLS, LVEF, and LAVI and incremental to LGE. Including LA conduit strain in DCM patient management should be considered to improve risk stratification.     

Prognostic Implications of Progressive Systemic Ventricular Dysfunction in Congenitally Corrected Transposition of Great Arteries

ObjectivesThe purpose of this study was to determine the risk factors for and prognostic implications of progressive right ventricular systolic dysfunction (RVD) in adults with congenitally corrected transposition of great arteries.BackgroundThere are no effective therapies for RVD; hence the need to identify and modify risk factors for progressive RVD.MethodsRV systolic function was assessed by using RV longitudinal strain (RV-LS). The first echocardiogram (baseline echocardiogram) and all subsequent annual echocardiograms performed within 5 years from the baseline echocardiogram were analyzed. Progressive RVD (temporal decline in RV-LS) was assessed as the average annual change in RV-LS within 5 years of imaging follow-up.ResultsOf 186 patients (mean age 40 ± 12 years), the RV-LS at baseline was –17% ± 4%, and the annual decline in RV-LS was –4% (95% CI: –6 to –2). The risk factors for progressive RVD were left ventricular (LV) systolic dysfunction, LV pacing, and systemic hypertension. Cardiovascular events (heart failure hospitalization, heart transplant, and death) occurred in 57 (27%) patients. Progressive RVD was associated with cardiovascular events, independent of RV systolic function at baseline. In subgroup analyses assessing impact of therapies (medical therapy, cardiac resynchronization therapy, and tricuspid valve replacement), only tricuspid valve replacement was associated with improvement in RV systolic function when performed before onset of RVD.ConclusionsPatients with congenitally corrected transposition of great arteries were at risk for progressive RVD, and the risk factors for progressive RVD were LV pacing, systemic hypertension, and concomitant LV dysfunction. Further studies are required to determine whether strict blood pressure control and early tricuspid valve replacement will prevent progressive RVD.     

Prognostic Value of Feature-Tracking Right Ventricular Longitudinal Strain in Severe Functional Tricuspid Regurgitation: A Multicenter Study

ObjectivesThis study sought to evaluate the prognostic value of cardiac magnetic resonance (CMR) feature-tracking–derived right ventricular (RV) free wall longitudinal strain (RVFWLS) in a large multicenter population of patients with severe functional tricuspid regurgitation.BackgroundTricuspid regurgitation imposes a volume overload on the RV that can lead to progressive RV dilation and dysfunction. Overt RV dysfunction is associated with poor prognosis and increased operative risk. Abnormalities of myocardial strain may provide the earliest evidence of ventricular dysfunction. CMR feature-tracking techniques now allow assessment of strain from routine cine images, without specialized pulse sequences. Whether abnormalities of RV strain measured using CMR feature tracking have prognostic value in patients with tricuspid regurgitation is unknown.MethodsConsecutive patients with severe functional tricuspid regurgitation undergoing CMR at 4 U.S. medical centers were included in this study. Feature-tracking RVFWLS was calculated from 4-chamber cine views. The primary endpoint was all-cause death. Cox proportional hazards regression modeling was used to examine the independent association between RVFWLS and death. The incremental prognostic value of RVFWLS was assessed in nested models.ResultsOf the 544 patients in this study, 128 died during a median follow-up of 6 years. By Kaplan-Meier analysis, patients with RVFWLS ≥median (−16%) had significantly reduced event-free survival compared with those with RVFWLS <median (log-rank p < 0.001). By Cox multivariable regression modeling, RVFWLS was associated with increased risk-of-death after adjustment for clinical and imaging risk factors, including RV size and ejection fraction (hazard ratio: 1.14 per %; p < 0.001). Addition of RVFWLS in this model resulted in significant improvement in the global chi-square (31 to 78; p < 0.001).ConclusionsCMR feature-tracking–derived RVFWLS is an independent predictor of mortality in patients with severe functional tricuspid regurgitation, incremental to common clinical and imaging risk factors.     

Prognostic Value of Initial Left Ventricular Remodeling in Patients With Reperfused STEMI

ObjectivesThis study sought to establish the best definition of left ventricular adverse remodeling (LVAR) to predict outcomes and determine whether its assessment adds prognostic information to that obtained by early cardiac magnetic resonance (CMR).BackgroundLVAR, usually defined as an increase in left ventricular end-diastolic volume (LVEDV) is the main cause of heart failure after an ST-segment elevated myocardial infarction; however, the role of assessment of LVAR in predicting cardiovascular events remains controversial.MethodsPatients with ST-segment elevated myocardial infarction who received percutaneous coronary intervention within 6 h of symptom onset were included (n = 498). CMR was performed during hospitalization (6.2 ± 2.6 days) and after 6 months (6.1 ± 1.8 months). The optimal threshold values of the LVEDV increase and the LV ejection fraction decrease associated with the primary endpoint were ascertained. Primary outcome was a composite of cardiovascular mortality, hospitalization for heart failure, or ventricular arrhythmia.ResultsThe study was completed by 374 patients. Forty-nine patients presented the primary endpoint during follow-up (72.9 ± 42.8 months). Values that maximized the ability to identify patients with and without outcomes were a relative rise in LVEDV of 15% (hazard ratio [HR]: 2.1; p = 0.007) and a relative fall in LV ejection fraction of 3% (HR: 2.5; p = 0.001). However, the predictive model (using C-statistic analysis) failed to demonstrate that direct observation of LVAR at 6 months adds information to data from early CMR in predicting outcomes (C-statistic: 0.723 vs. 0.795).ConclusionsThe definition of LVAR that best predicts adverse cardiovascular events should consider both the increase in LVEDV and the reduction in LV ejection fraction. However, assessment of LVAR does not improve information provided by the early CMR.     

Emerging Techniques for Risk Stratification in Nonischemic Dilated Cardiomyopathy: JACC Review Topic of the Week

Dilated cardiomyopathy (DCM) is a common condition, which carries significant mortality from sudden cardiac death and pump failure. Left ventricular ejection fraction has conventionally been used as a risk marker for sudden cardiac death, but has performed poorly in trials. There have been significant advances in the areas of cardiac magnetic resonance imaging and genetics, which are able to provide useful rick prediction in DCM. Biomarkers and cardiopulmonary exercise testing are well validated in the prediction of risk in heart failure; however, they have been tested less specifically in the DCM setting. This review will discuss these methods with a view toward multiparametric risk assessment in DCM with the hope of creating parametric risk models to predict sudden cardiac death and pump failure in the DCM population.     

Right Ventricular Contraction Patterns in Patients Undergoing Transcatheter Tricuspid Valve Repair for Severe Tricuspid Regurgitation

ObjectivesThis study investigated patterns of right ventricular (RV) contraction by using cardiac magnetic resonance (CMR) imaging in patients undergoing transcatheter tricuspid valve repair (TTVR).BackgroundThe role of RV function in patients with severe tricuspid regurgitation undergoing TTVR is poorly understood.MethodsGlobal RV dysfunction was defined as CMR-derived RV ejection fraction (RVEF) ≤45% and longitudinal RV dysfunction was defined as tricuspid annular plane systolic excursion (TAPSE) <17 mm on echocardiography. Patients were stratified into 3 types of RV contraction: type I, TAPSE ≥17 and RVEF >45%; type II, TAPSE <17 and RVEF >45%; and type III, TAPSE <17 and RVEF ≤45%. CMR feature tracking was performed to assess longitudinal and circumferential RV strain. The primary outcome was a composite of all-cause mortality or first heart failure hospitalization.ResultsOf 79 patients (median age 79 years, 51% female), 18 (23%) presented with global and 40 (51%) presented with longitudinal RV dysfunction. The composite outcome occurred in 22 patients (median follow-up 362 days). Global RV dysfunction but not longitudinal RV dysfunction (hazard ratio: 6.62; 95% confidence interval: 2.77-15.77; and hazard ratio: 1.30; 95% confidence interval: 0.55-3.08, respectively) was associated with the composite outcome. Compared with type I RV contraction, patients with type II RV contraction exhibited increased circumferential strain, with a preservation of RVEF despite diminished longitudinal strain. Patients with type III RV contraction exhibited both diminished longitudinal and circumferential strain, resulting in an impaired RVEF. Patients with type III RV contraction showed the worst survival (P < 0.001).ConclusionsGlobal RV dysfunction is a predictor of outcomes among TTVR patients. Tricuspid regurgitation patients can be stratified into 3 types of RV contraction, in which a loss of longitudinal function can be compensated by increasing circumferential function, preserving RVEF and favorable outcomes.     

Advanced Therapies for Ventricular Arrhythmias in Patients With Chagasic Cardiomyopathy: JACC State-of-the-Art Review

Chagas disease is caused by infection from the protozoan parasite Trypanosoma cruzi. Although it is endemic to Latin America, global migration has led to an increased incidence of Chagas in Europe, Asia, Australia, and North America. Following acute infection, up to 30% of patients will develop chronic Chagas disease, with most patients developing Chagasic cardiomyopathy. Chronic Chagas cardiomyopathy is highly arrhythmogenic, with estimated annual rates of appropriate implantable cardioverter-defibrillator therapies and electrical storm of 25% and 9.1%, respectively. Managing arrhythmias in patients with Chagasic cardiomyopathy is a major challenge for the clinical electrophysiologist, requiring intimate knowledge of cardiac anatomy, advanced training, and expertise. Endocardial-epicardial mapping and ablation strategy is needed to treat arrhythmias in this patient population, owing to the suboptimal long-term success rate of endocardial mapping and ablation alone. We also describe innovative approaches to improve acute and long-term clinical outcomes in patients with refractory ventricular arrhythmias following catheter ablation, such as bilateral cervicothoracic sympathectomy and bilateral renal denervation, among others.     

Impact of Right Ventricular Dysfunction on Outcomes After Transcatheter Edge-to-Edge Repair for Secondary Mitral Regurgitation

ObjectivesThis study sought to assess the impact of right ventricular dysfunction (RVD) as defined by impaired right ventricular-to-pulmonary artery (RV-PA) coupling, on survival after edge-to-edge transcatheter mitral valve repair (TMVR) for severe secondary mitral regurgitation (SMR).BackgroundConflicting data exist regarding the benefit of TMVR in severe SMR. A possible explanation could be differences in RVD.MethodsUsing data from the EuroSMR (European Registry on Outcomes in Secondary Mitral Regurgitation) registry, this study compared the characteristics and outcomes of SMR patients undergoing TMVR, according to their RV-PA coupling, assessed by tricuspid annular plane systolic excursion-to-systolic pulmonary artery pressure (TAPSE/sPAP) ratio.ResultsOverall, 817 patients with severe SMR and available RV-PA coupling assessment underwent TMVR in the participating centers. RVD was present in 211 patients (25.8% with a TAPSE/sPAP ratio <0.274 mm/mm Hg). Although all patients demonstrated significant improvement in their New York Heart Association (NYHA) functional class, there was a trend toward a lower rate of NYHA functional class I or II among patients with RVD (56.5% vs. 65.5%, respectively; p = 0.086) after TMVR. Survival rates at 1 and 2 years were lower among patients with RVD (70.2% vs. 84.0%, respectively; p < 0.001; and 53.4% vs. 73.1%, respectively; p < 0.001). On multivariate analysis, a reduced TAPSE/sPAP ratio was a strong predictor of mortality (odds ratio: 1.62; 95% confidence interval: 1.14 to 2.31; p = 0.007).ConclusionsRVD, as shown by impairment of RV-PA coupling, is a major predictor of adverse outcome in patients undergoing TMVR for severe SMR. The often neglected functional and anatomic RV parameters should be systematically assessed when planning TMVR procedures for patients with severe SMR.