Pregnancy in women with dilated cardiomyopathy genetic variants.

INTRODUCTION AND OBJECTIVES: Limited information is available on the safety of pregnancy in patients with genetic dilated cardiomyopathy (DCM) and in carriers of DCM-causing genetic variants without the DCM phenotype. We assessed cardiac, obstetric, and fetal or neonatal outcomes in this group of patients. METHODS: We studied 48 women carrying pathogenic or likely pathogenic DCM-associated variants (30 with DCM and 18 without DCM) who had 83 pregnancies. Adverse cardiac events were defined as heart failure (HF), sustained ventricular tachycardia, ventricular assist device implantation, heart transplant, and/or maternal cardiac death during pregnancy, or labor and delivery, and up to the sixth postpartum month. RESULTS: A total of 15 patients, all with DCM (31% of the total cohort and 50% of women with DCM) experienced adverse cardiac events. Obstetric and fetal or neonatal complications were observed in 14% of pregnancies (10 in DCM patients and 2 in genetic carriers). We analyzed the 30 women who had been evaluated before their first pregnancy (12 with overt DCM and 18 without the phenotype). Five of the 12 (42%) women with DCM had adverse cardiac events despite showing NYHA class I or II before pregnancy. Most of these women had a history of cardiac events before pregnancy (80%). Among the 18 women without phenotype, 3 (17%) developed DCM toward the end of pregnancy. CONCLUSIONS: Cardiac complications during pregnancy and postpartum were common in patients with genetic DCM and were primarily related to HF. Despite apparently good tolerance of pregnancy in unaffected genetic carriers, pregnancy may act as a trigger for DCM onset in a subset of these women.

Phenotyping patients with ischaemic heart disease at risk of developing heart failure: an analysis of the HOMAGE trial.

AIMS: We aim to characterize the clinical and proteomic profiles of patients at risk of developing heart failure (HF), with and without coronary artery disease (CAD) or prior myocardial infarction (MI). METHODS AND RESULTS: HOMAGE evaluated the effect of spironolactone on plasma and serum markers of fibrosis over 9 months of follow-up in participants with (or at risk of having) CAD, and raised natriuretic peptides. In this post hoc analysis, patients were classified as (i) neither CAD nor MI; (ii) CAD; or (iii) MI. Proteomic between-group differences were evaluated through logistic regression and narrowed using backward stepwise selection and bootstrapping. Among the 527 participants, 28% had neither CAD or MI, 31% had CAD, and 41% had prior MI. Compared with people with neither CAD nor MI, those with CAD had higher baseline plasma concentrations of matrix metalloproteinase-7 (MMP-7), galectin-4 (GAL4), plasminogen activator inhibitor 1 (PAI-1), and lower plasma peptidoglycan recognition protein 1 (PGLYRP1), whilst those with a history of MI had higher plasma MMP-7, neurotrophin-3 (NT3), pulmonary surfactant-associated protein D (PSPD), and lower plasma tumour necrosis factor-related activation-induced cytokine (TRANCE). Proteomic signatures were similar for patients with CAD or prior MI. Treatment with spironolactone was associated with an increase of MMP7, NT3, and PGLYRP1 at 9 months. CONCLUSIONS: In patients at risk of developing HF, those with CAD or MI had a different proteomic profile regarding inflammatory, immunological, and collagen catabolic processes.

Left Atrial Function in Patients with Titin Cardiomyopathy.

BACKGROUND: Truncating variants in titin (TTNtv) are the most prevalent genetic etiology of dilated cardiomyopathy (DCM). Although TTNtv has been associated with atrial fibrillation, it remains unknown whether and how left atrial (LA) function differs between patients with DCM with and without TTNtv. We aimed to determine and compare LA function in patients with DCM with and without TTNtv and to evaluate whether and how left ventricular (LV) function affects the LA using computational modeling. METHODS AND RESULTS: Patients with DCM from the Maastricht DCM registry that underwent genetic testing and cardiovascular magnetic resonance (CMR) were included in the current study. Subsequent computational modeling (CircAdapt model) was performed to identify potential LV and LA myocardial hemodynamic substrates. In total, 377 patients with DCM (n = 42 with TTNtv, n = 335 without a genetic variant) were included (median age 55 years, interquartile range [IQR] 46-62 years, 62% men). Patients with TTNtv had a larger LA volume and decreased LA strain compared with patients without a genetic variant (LA volume index 60 mLm-2 [IQR 49-83] vs 51 mLm-2 [IQR 42-64]; LA reservoir strain 24% [IQR 10-29] vs 28% [IQR 20-34]; LA booster strain 9% [IQR 4-14] vs 14% [IQR 10-17], respectively; all P < .01). Computational modeling suggests that while the observed LV dysfunction partially explains the observed LA dysfunction in the patients with TTNtv, both intrinsic LV and LA dysfunction are present in patients with and without a TTNtv. CONCLUSIONS: Patients with DCM with TTNtv have more severe LA dysfunction compared with patients without a genetic variant. Insights from computational modeling suggest that both intrinsic LV and LA dysfunction are present in patients with DCM with and without TTNtv.

Biomarkers of Collagen Metabolism Are Associated with Left Ventricular Function and Prognosis in Dilated Cardiomyopathy: A Multi-Modal Study.

BACKGROUND: Collagen cross-linking is a fundamental process in dilated cardiomyopathy (DCM) and occurs when collagen deposition exceeds degradation, leading to impaired prognosis. This study investigated the associations of collagen-metabolism biomarkers with left ventricular function and prognosis in DCM. METHODS: DCM patients who underwent endomyocardial biopsy, blood sampling, and cardiac MRI were included. The primary endpoint included death, heart failure hospitalization, or life-threatening arrhythmias, with a follow-up of 6 years (5-8). RESULTS: In total, 209 DCM patients were included (aged 54 ± 13 years, 65% male). No associations were observed between collagen volume fraction, circulating carboxy-terminal propeptide of procollagen type-I (PICP), or collagen type I carboxy-terminal telopeptide [CITP] and matrix metalloproteinase [MMP]-1 ratio and cardiac function parameters. However, CITP:MMP-1 was significantly correlated with global longitudinal strain (GLS) in the total study sample (R = -0.40, p < 0.0001; lower CITP:MMP-1 ratio was associated with impaired GLS), with even stronger correlations in patients with LVEF > 40% (R = -0.70, p < 0.0001). Forty-seven (22%) patients reached the primary endpoint. Higher MMP-1 levels were associated with a worse outcome, even after adjustment for clinical and imaging predictors (1.026, 95% CI 1.002-1.051, p = 0.037), but CITP and CITP:MMP-1 were not. Combining MMP-1 and PICP improved the goodness-of-fit (LHR36.67, p = 0.004). CONCLUSION: The degree of myocardial cross-linking (CITP:MMP-1) is associated with myocardial longitudinal contraction, and MMP-1 is an independent predictor of outcome in DCM patients.

Cardiac Inflammation in Adult-Onset Genetic Dilated Cardiomyopathy.

Dilated cardiomyopathy (DCM) has a genetic cause in up to 40% of cases, with differences in disease penetrance and clinical presentation, due to different exogeneous triggers and implicated genes. Cardiac inflammation can be the consequence of an exogeneous trigger, subsequently unveiling a phenotype. The study aimed to determine cardiac inflammation in a cohort of genetic DCM patients and investigate whether it associated with a younger disease onset. The study included 113 DCM patients with a genetic etiology, of which 17 had cardiac inflammation as diagnosed in an endomyocardial biopsy. They had a significant increased cardiac infiltration of white blood, cytotoxic T, and T-helper cells (p < 0.05). Disease expression was at a younger age in those patients with cardiac inflammation, compared to those without inflammation (p = 0.015; 50 years (interquartile range (IQR) 42-53) versus 53 years (IQR 46-61). However, cardiac inflammation was not associated with a higher incidence of all-cause mortality, heart failure hospitalization, or life-threatening arrhythmias (hazard ratio 0.85 [0.35-2.07], p = 0.74). Cardiac inflammation is associated with an earlier disease onset in patients with genetic DCM. This might indicate that myocarditis is an exogeneous trigger unveiling a phenotype at a younger age in patients with a genetic susceptibility, or that cardiac inflammation resembles a 'hot-phase' of early-onset disease.

Protein Biomarkers of New-Onset Heart Failure: Insights From the Heart Omics and Ageing Cohort, the Atherosclerosis Risk in Communities Study, and the Framingham Heart Study.

BACKGROUND: We sought to identify protein biomarkers of new-onset heart failure (HF) in 3 independent cohorts (HOMAGE cohort [Heart Omics and Ageing], ARIC study [Atherosclerosis Risk in Communities], and FHS [Framingham Heart Study]) and assess if and to what extent they improve HF risk prediction compared to clinical risk factors alone. METHODS: A nested case-control design was used with cases (incident HF) and controls (without HF) matched on age and sex within each cohort. Plasma concentrations of 276 proteins were measured at baseline in ARIC (250 cases/250 controls), FHS (191/191), and HOMAGE cohort (562/871). RESULTS: In single protein analysis, after adjusting for matching variables and clinical risk factors (and correcting for multiple testing), 62 proteins were associated with incident HF in ARIC, 16 in FHS, and 116 in HOMAGE cohort. Proteins associated with incident HF in all cohorts were BNP (brain natriuretic peptide), NT-proBNP (N-terminal pro-B-type natriuretic peptide), eukaryotic translation initiation factor 4E-BP1 (4E-binding protein 1), hepatocyte growth factor (HGF), Gal-9 (galectin-9), TGF-alpha (transforming growth factor alpha), THBS2 (thrombospondin-2), and U-PAR (urokinase plasminogen activator surface receptor). The increment in C-index for incident HF based on a multiprotein biomarker approach, in addition to clinical risk factors and NT-proBNP, was 11.1% (7.5%-14.7%) in ARIC, 5.9% (2.6%-9.2%) in FHS, and 7.5% (5.4%-9.5%) in HOMAGE cohort, all P<0.001), each of which was a larger increase than that for NT-proBNP on top of clinical risk factors. Complex network analysis revealed a number of overrepresented pathways related to inflammation (eg, tumor necrosis factor and interleukin) and remodeling (eg, extracellular matrix and apoptosis). CONCLUSIONS: A multiprotein biomarker approach improves prediction of incident HF when added to natriuretic peptides and clinical risk factors.

Effect of Spironolactone on QRS Duration in Patients at Risk for Heart Failure (from the HOMAGE Trial).

The QRS duration can be easily obtained from a 12-lead electrocardiogram. Increased QRS duration reflects greater ventricular activation times and often ventricular dyssynchrony. Dyssynchrony causes an impairment of the global cardiac function and adversely affects the prognosis of patients with heart failure (HF). Little is known about the impact of pharmacologic therapies on the QRS duration, particularly for patients with presymptomatic HF with a preserved left ventricular (LV) ejection fraction (i.e., stage B HF with preserved ejection fraction [HFpEF]). The HOMAGE (Heart OMics in AGEing) trial enrolled patients at risk factors for developing HF and assigned them to receive either spironolactone or the usual care for approximately 9 months in a randomized manner. This analysis reports the effect of spironolactone on the QRS duration. A total of 525 patients was included in the analysis. The median (percentile25-75) QRS duration at baseline was 92 (84 to 106) ms. Spironolactone reduced the QRS duration at month 9 by -2.8, 95% confidence interval -4.6 to -1.0 ms, p = 0.003. No significant associations were found between month 9 changes in the QRS duration and corresponding changes in the LV ejection fraction, LV mass, LV end-diastolic volume, blood pressure, N-terminal pro-brain natriuretic peptide, and procollagen type I carboxy-terminal propeptide (all p >0.05). This analysis shows that for patients with stage B HFpEF, therapy with spironolactone for 9 months shortened the QRS duration, an effect that was not associated with reductions in LV mass or volume, supporting the hypothesis that spironolactone has direct beneficial effects to improve myocardial electrical activation in patients with stage B HFpEF.

Left Atrial Reverse Remodeling in Dilated Cardiomyopathy.

BACKGROUND: Left atrial (LA) dilation is associated with a worse prognosis in several cardiovascular settings, but therapies can promote LA reverse remodeling. The aim of this study was to characterize and define the prognostic implications of LA volume index (LAVI) reduction in patients with dilated cardiomyopathy (DCM). METHODS: Consecutive patients with DCM from two tertiary care centers, with available echocardiograms at baseline and at 1-year follow-up, were retrospectively analyzed. LA dilation was defined as LAVI > 34 mL/m2, and change in LAVI (ΔLAVI) was defined as the 1-year relative LAVI reduction. The outcome was a composite of death, heart transplantation (HTx), or heart failure hospitalization (HFH). RESULTS: Five hundred sixty patients were included (mean age, 54 ± 13 years; mean left ventricular ejection fraction, 31 ± 10%; mean LAVI, 45 ± 18 mL/m2). Baseline LAVI had a non-linear association with the risk for death, HTx, or HFH, independent of age, left ventricular ejection fraction, mitral regurgitation, and medical therapy (P < .01). At 1-year follow-up, LAVI decreased in 374 patients (67%; median ΔLAVI, -24%; interquartile range, -37% to -11%). Factors independently associated with ΔLAVI were higher baseline LAVI and lower baseline left ventricular ejection fraction. After multivariable adjustment, ΔLAVI showed a linear association with the risk for death, HTx, or HFH (hazard ratio, 0.96 per 5% decrease; 95% CI, 0.93-0.99; P = .042). At 1-year follow-up, patients with reductions in LAVI of >10% and LAVI normalization (i.e., follow-up LAVI ≤ 34 mL/m2; 31% of the overall cohort) were at lower risk for death, HTx, or HFH (hazard ratio, 0.37; 95% CI, 0.35-0.97; P = .028). CONCLUSIONS: In a large cohort of patients with DCM, 1-year reduction in LAVI was observed in a number of patients. The association between reduction in LAVI and death, HTx, or HFH suggests that LA structural reverse remodeling might be considered an additional parameter useful in the individualized risk stratification of patients with DCM.

Genetic Architecture of Acute Myocarditis and the Overlap With Inherited Cardiomyopathy.

BACKGROUND: Acute myocarditis is an inflammatory condition that may herald the onset of dilated cardiomyopathy (DCM) or arrhythmogenic cardiomyopathy (ACM). We investigated the frequency and clinical consequences of DCM and ACM genetic variants in a population-based cohort of patients with acute myocarditis. METHODS: This was a population-based cohort of 336 consecutive patients with acute myocarditis enrolled in London and Maastricht. All participants underwent targeted DNA sequencing for well-characterized cardiomyopathy-associated genes with comparison to healthy controls (n=1053) sequenced on the same platform. Case ascertainment in England was assessed against national hospital admission data. The primary outcome was all-cause mortality. RESULTS: Variants that would be considered pathogenic if found in a patient with DCM or ACM were identified in 8% of myocarditis cases compared with <1% of healthy controls (P=0.0097). In the London cohort (n=230; median age, 33 years; 84% men), patients were representative of national myocarditis admissions (median age, 32 years; 71% men; 66% case ascertainment), and there was enrichment of rare truncating variants (tv) in ACM-associated genes (3.1% of cases versus 0.4% of controls; odds ratio, 8.2; P=0.001). This was driven predominantly by DSP-tv in patients with normal LV ejection fraction and ventricular arrhythmia. In Maastricht (n=106; median age, 54 years; 61% men), there was enrichment of rare truncating variants in DCM-associated genes, particularly TTN-tv, found in 7% (all with left ventricular ejection fraction <50%) compared with 1% in controls (odds ratio, 3.6; P=0.0116). Across both cohorts over a median of 5.0 years (interquartile range, 3.9-7.8 years), all-cause mortality was 5.4%. Two-thirds of deaths were cardiovascular, attributable to worsening heart failure (92%) or sudden cardiac death (8%). The 5-year mortality risk was 3.3% in genotype-negative patients versus 11.1% for genotype-positive patients (Padjusted=0.08). CONCLUSIONS: We identified DCM- or ACM-associated genetic variants in 8% of patients with acute myocarditis. This was dominated by the identification of DSP-tv in those with normal left ventricular ejection fraction and TTN-tv in those with reduced left ventricular ejection fraction. Despite differences between cohorts, these variants have clinical implications for treatment, risk stratification, and family screening. Genetic counseling and testing should be considered in patients with acute myocarditis to help reassure the majority while improving the management of those with an underlying genetic variant.

Dyskalemia in people at increased risk for heart failure: findings from the heart 'OMics' in AGEing (HOMAGE) trial.

AIMS: In people at risk of heart failure (HF) enrolled in the Heart 'OMics' in AGEing (HOMAGE) trial, spironolactone reduced circulating markers of collagen synthesis, natriuretic peptides, and blood pressure and improved cardiac structure and function. In the present report, we explored factors associated with dyskalaemia. METHODS AND RESULTS: The HOMAGE trial was an open-label study comparing spironolactone (up to 50 mg/day) versus standard care in people at risk for HF. After randomization, serum potassium was assessed at 1 and 9 months and was defined as low when ≤3.5 mmol/L (hypokalaemia) and high when ≥5.5 mmol/L (hyperkalaemia). Multivariable logistic regression models were constructed to identify clinical predictors of dyskalaemia. A total of 513 participants (median age 74 years, 75% men, median estimated glomerular filtration rate 71 mL/min/1.73 m2 ) had serum potassium available and were included in this analysis. At randomization, 88 had potassium < 4.0 mmol/L, 367 had potassium 4.0-5.0 mmol/L, and 58 had potassium > 5.0 mmol/L. During follow-up, on at least one occasion, a serum potassium < 3.5 mmol/L was observed in 6 (1.2%) and <4.0 mmol/L in 46 (9%) participants, while a potassium > 5.0 mmol/L was observed in 38 (8%) and >5.5 mmol/L in 5 (1.0%) participants. The median (percentile25-75 ) increase in serum potassium with spironolactone during the study was 0.23 (0.16; 0.29) mmol/L. Because of the low incidence of dyskalaemia, for regression analysis, hypokalaemia and hyperkalaemia thresholds were set at <4.0 and >5.0 mmol/L, respectively. The occurrence of a serum potassium > 5.0 mmol/L during follow-up was positively associated with the presence of diabetes mellitus {odds ratio [OR]: 1.21 [95% confidence interval (CI) 2.14; 3.79]} and randomization to spironolactone (OR: 2.83 [95% CI 1.49; 5.37]). Conversely, the occurrence of a potassium concentration < 4.0 mmol/L was positively associated with the use of thiazides (OR: 2.39 [95% CI 1.32; 4.34]), blood urea concentration (OR: 2.15 [95% CI 1.34; 3.39] per 10 mg/dL), and history of hypertension (OR: 2.32 [95% CI 1.02; 5.29]) and negatively associated with randomization to spironolactone (OR: 0.30 [95% CI 0.18; 0.52]). CONCLUSIONS: In people at risk for developing HF and with relatively normal renal function, spironolactone reduced the risk of hypokalaemia and, at the doses used, was not associated with the occurrence of clinically meaningful hyperkalaemia.

Interatrial Block Predicts Life-Threatening Arrhythmias in Dilated Cardiomyopathy.

Background Interatrial block (IAB) has been associated with supraventricular arrhythmias and stroke, and even with sudden cardiac death in the general population. Whether IAB is associated with life-threatening arrhythmias (LTA) and sudden cardiac death in dilated cardiomyopathy (DCM) remains unknown. This study aimed to determine the association between IAB and LTA in ambulant patients with DCM. Methods and Results A derivation cohort (Maastricht Dilated Cardiomyopathy Registry; N=469) and an external validation cohort (Utrecht Cardiomyopathy Cohort; N=321) were used for this study. The presence of IAB (P-wave duration>120 milliseconds) or atrial fibrillation (AF) was determined using digital calipers by physicians blinded to the study data. In the derivation cohort, IAB and AF were present in 291 (62%) and 70 (15%) patients with DCM, respectively. LTA (defined as sudden cardiac death, justified shock from implantable cardioverter-defibrillator or anti-tachypacing, or hemodynamic unstable ventricular fibrillation/tachycardia) occurred in 49 patients (3 with no IAB, 35 with IAB, and 11 patients with AF, respectively; median follow-up, 4.4 years [2.1; 7.4]). The LTA-free survival distribution significantly differed between IAB or AF versus no IAB (both P<0.01), but not between IAB versus AF (P=0.999). This association remained statistically significant in the multivariable model (IAB: HR, 4.8 (1.4-16.1), P=0.013; AF: HR, 6.4 (1.7-24.0), P=0.007). In the external validation cohort, the survival distribution was also significantly worse for IAB or AF versus no IAB (P=0.037; P=0.005), but not for IAB versus AF (P=0.836). Conclusions IAB is an easy to assess, widely applicable marker associated with LTA in DCM. IAB and AF seem to confer similar risk of LTA. Further research on IAB in DCM, and on the management of IAB in DCM is warranted.

The association between markers of type I collagen synthesis and echocardiographic response to spironolactone in patients at risk of heart failure: findings from the HOMAGE trial.

AIMS: Procollagen type I C-terminal propeptide (PICP) and procollagen type III N-terminal propeptide (PIIINP) are markers reflecting collagen synthesis in cardiac fibrosis. However, they may be influenced by the presence of non-cardiac comorbidities (e.g. ageing, obesity, renal impairment). Understanding the associations between markers of collagen synthesis and abnormalities of cardiac structure and function is important to screen for myocardial fibrosis and monitor the antifibrotic effect of medications. METHODS AND RESULTS: The HOMAGE (Heart 'OMics' in AGEing) trial showed that spironolactone decreased serum PICP concentrations and improved cardiac remodelling over 9 months in a population at risk of developing heart failure (HF). We evaluated the associations between echocardiographic variables, PICP, PIIINP and galectin-3 at baseline and during the course of the trial. Among 527 individuals (74 ± 7 years, 26% women), median serum concentrations of PICP, PIIINP and galectin-3 were 80.6 µg/L (65.1-97.0), 3.9 µg/L (3.1-5.0), and 16.1 µg/L (13.5-19.7), respectively. After adjustment for potential confounders, higher serum PICP was significantly associated with left ventricular hypertrophy, left atrial enlargement, and greater ventricular stiffness (all p < 0.05), whereas serum PIIINP and galectin-3 were not (all p > 0.05). In patients treated with spironolactone, a reduction in serum PICP during the trial was associated with a decrease in E/e' (adjusted-beta = 0.93, 95% confidence interval 0.14-1.73; p = 0.022). CONCLUSIONS: In individuals at high risk of developing HF, serum PICP was associated with cardiac structural and functional abnormalities, and a decrease in PICP with spironolactone was correlated with improved diastolic dysfunction as assessed by E/e'. In contrast, no such associations were present for serum PIIINP and galectin-3.

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

BACKGROUND: The 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. OBJECTIVES: The goal of this study was to evaluate the prognostic value of CMR-derived LA strain in DCM. METHODS: Patients 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. RESULTS: A 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). CONCLUSIONS: LA 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.

Precision Phenotyping of Dilated Cardiomyopathy Using Multidimensional Data.

BACKGROUND: Dilated cardiomyopathy (DCM) is a final common manifestation of heterogenous etiologies. Adverse outcomes highlight the need for disease stratification beyond ejection fraction. OBJECTIVES: The purpose of this study was to identify novel, reproducible subphenotypes of DCM using multiparametric data for improved patient stratification. METHODS: Longitudinal, observational UK-derivation (n = 426; median age 54 years; 67% men) and Dutch-validation (n = 239; median age 56 years; 64% men) cohorts of DCM patients (enrolled 2009-2016) with clinical, genetic, cardiovascular magnetic resonance, and proteomic assessments. Machine learning with profile regression identified novel disease subtypes. Penalized multinomial logistic regression was used for validation. Nested Cox models compared novel groupings to conventional risk measures. Primary composite outcome was cardiovascular death, heart failure, or arrhythmia events (median follow-up 4 years). RESULTS: In total, 3 novel DCM subtypes were identified: profibrotic metabolic, mild nonfibrotic, and biventricular impairment. Prognosis differed between subtypes in both the derivation (P < 0.0001) and validation cohorts. The novel profibrotic metabolic subtype had more diabetes, universal myocardial fibrosis, preserved right ventricular function, and elevated creatinine. For clinical application, 5 variables were sufficient for classification (left and right ventricular end-systolic volumes, left atrial volume, myocardial fibrosis, and creatinine). Adding the novel DCM subtype improved the C-statistic from 0.60 to 0.76. Interleukin-4 receptor-alpha was identified as a novel prognostic biomarker in derivation (HR: 3.6; 95% CI: 1.9-6.5; P = 0.00002) and validation cohorts (HR: 1.94; 95% CI: 1.3-2.8; P = 0.00005). CONCLUSIONS: Three reproducible, mechanistically distinct DCM subtypes were identified using widely available clinical and biological data, adding prognostic value to traditional risk models. They may improve patient selection for novel interventions, thereby enabling precision medicine.

The HFA-PEFF score identifies 'early-HFpEF' phenogroups associated with distinct biomarker profiles.

AIMS: The HFA-PEFF score was developed to optimize diagnosis and to aid in early recognition of heart failure (HF) with preserved ejection fraction (HFpEF) in patients who present with HF-like symptoms. Recognizing early-HFpEF phenogroups is essential to better understand progression towards overt HFpEF and pave the way for early intervention and treatment. Whether the HFA-PEFF domain scores can identify 'early-HFpEF' phenogroups remains unknown. The aims of this pilot study are to (i) identify distinct phenogroups by cluster analysis of HFA-PEFF domain scores in subjects that present with HF-like symptoms and (ii) study whether these phenogroups may be associated with distinct blood proteome profiles. METHODS AND RESULTS: Subjects referred to the Cardiology Centers of the Netherlands, location Utrecht, with non-acute possibly cardiac-related symptoms (such as dyspnoea or fatigue) were prospectively enrolled in the HELPFul cohort (N = 507) and were included in the current analysis. Inclusion criteria for this study were (i) age ≥ 45 years and (ii) a left ventricular ejection fraction (LVEF) ≥ 50%, in the absence of a history of HF, coronary artery disease, congenital heart disease, or any previous cardiac interventions. Multinominal-based clustering with latent class model using the HFA-PEFF domain scores (functional, structural, and biomarker scores) as input was used to detect distinct phenotypic clusters. For each bootstrapping run, the 92 Olink proteins were analysed for their association with the identified phenogroups. Four distinct phenogroups were identified in the current analysis (validated by bootstrapping 1000×): (i) no left ventricular diastolic dysfunction (no LVDD, N = 102); (ii) LVDD with functional left ventricular (LV) abnormalities (N = 204); (iii) LVDD with functional and structural LV abnormalities (N = 204); and (iv) LVDD with functional and structural LV abnormalities and elevated BNP (N = 107). The HFA-PEFF total score risk categories significantly differed between the phenogroups (P < 0.001), with an increase of the HFA-PEFF score from Phenogroup 1 to 4 (low/intermediate/high HFA-PEFF risk score: Phenogroup 1: 88%/12%/0%; Phenogroup 2: 9%/91%/0%; Phenogroup 3: 0%/92%/8%; Phenogroup 4: 5%/83%/12%). Thirty-two out of the 92 Olink protein biomarkers significantly differed among the phenogroups. The top eight biomarkers-N-terminal prohormone brain natriuretic peptide, growth differentiation factor-15, matrix metalloproteinase-2, osteoprotegerin, tissue inhibitor of metalloproteinase-4, chitinase-3-like protein 1, insulin-like growth factor-binding protein 2, and insulin-like growth factor-binding protein 7-are mainly involved in inflammation and extracellular matrix remodelling, which are currently proposed key processes in HFpEF pathophysiology. CONCLUSIONS: This study identified distinct phenogroups by using the HFA-PEFF domain scores in ambulant subjects referred for HF-like symptoms. The newly identified phenogroups accompanied by their circulating biomarkers profile might aid in a better understanding of the pathophysiological processes involved during the early stages of the HFpEF syndrome.