Comparison of diagnostic algorithms in clinically suspected viral myocarditis: agreement between cardiac magnetic resonance, endomyocardial biopsy and troponin T.

AIMS: Myocardial inflammation is increasingly detected non-invasively by tissue mapping with cardiovascular magnetic resonance (CMR). Intraindividual agreement with endomyocardial biopsy (EMB) or marker of myocardial injury, high-sensitive troponin (hs-cTnT) in patients with clinically suspected viral myocarditis not understood. METHODS AND RESULTS: Prospective multicentre study of consecutive patients with clinically suspected myocarditis who underwent blood testing for hs-cTnT, CMR and EMB as a part of diagnostic work-up. EMB was considered positive based on immunohistological criteria in line with the ESC definitions. CMR diagnoses employed tissue mapping using sequence-specific cut-off for native T1 and T2 mapping; active inflammation was defined as T1≥2SD and T2≥2SD above the mean of normal range. Hs-cTnT of greater than 13.9ng/1 was considered significant. A total of 114 patients (age (mean±SD) 54±16, 65% males) were included, of which 79(69%) had positive EMB-criteria, 64(56%) CMR criteria, and a total of 58 (51%) positive troponin. Agreement between EMB and CMR diagnostic criteria was poor (CMR vs. ESC: AUCs: 0.51 (0.39-0.62)). The agreement between the significant hs-cTnT rise and CMR-based diagnosis of myocarditis was good (AUC: 0.84 (0.68-0.92); p<0.001), but poor for EMB (0.50 (0.40-0.61). Hs-cTnT was significantly associated with native T1 and T2, hs-CRP and NT-pro BNP (r=0.37, r=0.35, r=0.30, r=0.25 p<0.001), but not immunohistochemical criteria or viral presence. CONCLUSIONS: In clinically suspected viral myocarditis, all diagnostic approaches reflect the pathophysiological elements of myocardial inflammation, however the differing underlying drivers only partially overlap. The EMB and CMR diagnostic algorithms are neither interchangeable in terms of interpretation of myocardial inflammation nor in their relationship with myocardial injury.

Cardiac biomarkers in chronic kidney disease are independently associated with myocardial edema and diffuse fibrosis by cardiovascular magnetic resonance.

BACKGROUND: High sensitivity cardiac troponin T (hs-cTnT) and NT-pro-brain natriuretic peptide (NT-pro BNP) are often elevated in chronic kidney disease (CKD) and associated with both cardiovascular remodeling and outcome. Relationship between these biomarkers and quantitative imaging measures of myocardial fibrosis and edema by T1 and T2 mapping remains unknown. METHODS: Consecutive patients with established CKD and estimated glomerular filtration rate (eGFR) < 59 ml/min/1.73 m2 (n = 276) were compared to age/sex matched patients with eGFR ≥ 60 ml/min/1.73 m2 (n = 242) and healthy controls (n = 38). Comprehensive cardiovascular magnetic resonance (CMR) with native T1 and T2 mapping, myocardial ischemia and scar imaging was performed with venous sampling immediately prior to CMR. RESULTS: Patients with CKD showed significant cardiac remodeling in comparison with both healthy individuals and non-CKD patients, including a stepwise increase of native T1 and T2 (p < 0.001 between all CKD stages). Native T1 and T2 were the sole imaging markers independently associated with worsening CKD in patients [B = 0.125 (95% CI 0.022-0.235) and B = 0.272 (95% CI 0.164-0.374) with p = 0.019 and < 0.001 respectively]. At univariable analysis, both hs-cTnT and NT-pro BNP significantly correlated with native T1 and T2 in groups with eGFR 30-59 ml/min/1.73 m2 and eGFR < 29 ml/min/1.73 m2 groups, with associations being stronger at lower eGFR (NT-pro BNP (log transformed, lg10): native T1 r = 0.43 and r = 0.57, native T2 r = 0.39 and r = 0.48 respectively; log-transformed hs-cTnT(lg10): native T1 r = 0.23 and r = 0.43, native T2 r = 0.38 and r = 0.58 respectively, p < 0.001 for all, p < 0.05 for interaction). On multivariable analyses, we found independent associations of native T1 with NT-pro BNP [(B = 0.308 (95% CI 0.129-0.407), p < 0.001 and B = 0.334 (95% CI 0.154-0.660), p = 0.002 for eGFR 30-59 ml/min/1.73 m2 and eGFR < 29 ml/min/1.73 m2, respectively] and of T2 with hs-cTnT [B = 0.417 (95% CI 0.219-0.650), p < 0.001 for eGFR < 29 ml/min/1.73 m2]. CONCLUSIONS: We demonstrate independent associations between cardiac biomarkers with imaging markers of interstitial expansion, which are CKD-group specific. Our findings indicate the role of diffuse non-ischemic tissue processes, including excess of myocardial fluid in addition to diffuse fibrosis in CKD-related adverse remodeling.

Myocardial Fibrosis and Inflammation by CMR Predict Cardiovascular Outcome in People Living With HIV.

OBJECTIVES: The goal of this study was to examine prognostic relationships between cardiac imaging measures and cardiovascular outcome in people living with human immunodeficiency virus (HIV) (PLWH) on highly active antiretroviral therapy (HAART). BACKGROUND: PLWH have a higher prevalence of cardiovascular disease and heart failure (HF) compared with the noninfected population. The pathophysiological drivers of myocardial dysfunction and worse cardiovascular outcome in HIV remain poorly understood. METHODS: This prospective observational longitudinal study included consecutive PLWH on long-term HAART undergoing cardiac magnetic resonance (CMR) examination for assessment of myocardial volumes and function, T1 and T2 mapping, perfusion, and scar. Time-to-event analysis was performed from the index CMR examination to the first single event per patient. The primary endpoint was an adjudicated adverse cardiovascular event (cardiovascular mortality, nonfatal acute coronary syndrome, an appropriate device discharge, or a documented HF hospitalization). RESULTS: A total of 156 participants (62% male; age [median, interquartile range]: 50 years [42 to 57 years]) were included. During a median follow-up of 13 months (9 to 19 months), 24 events were observed (4 HF deaths, 1 sudden cardiac death, 2 nonfatal acute myocardial infarction, 1 appropriate device discharge, and 16 HF hospitalizations). Patients with events had higher native T1 (median [interquartile range]: 1,149 ms [1,115 to 1,163 ms] vs. 1,110 ms [1,075 to 1,138 ms]); native T2 (40 ms [38 to 41 ms] vs. 37 ms [36 to 39 ms]); left ventricular (LV) mass index (65 g/m2 [49 to 77 g/m2] vs. 57 g/m2 [49 to 64 g/m2]), and N-terminal pro-B-type natriuretic peptide (109 pg/l [25 to 337 pg/l] vs. 48 pg/l [23 to 82 pg/l]) (all p < 0.05). In multivariable analyses, native T1 was independently predictive of adverse events (chi-square test, 15.9; p < 0.001; native T1 [10 ms] hazard ratio [95% confidence interval]: 1.20 [1.08 to 1.33]; p = 0.001), followed by a model that also included LV mass (chi-square test, 17.1; p < 0.001). Traditional cardiovascular risk scores were not predictive of the adverse events. CONCLUSIONS: Our findings reveal important prognostic associations of diffuse myocardial fibrosis and LV remodeling in PLWH. These results may support development of personalized approaches to screening and early intervention to reduce the burden of HF in PLWH (International T1 Multicenter Outcome Study; NCT03749343).

Native T1 and T2 provide distinctive signatures in hypertrophic cardiac conditions - Comparison of uremic, hypertensive and hypertrophic cardiomyopathy.

AIMS: Profound left ventricular (LV) hypertrophy with diastolic dysfunction and heart failure is the cardinal manifestation of heart remodelling in chronic kidney disease (CKD). Previous studies related increased T1 mapping values in CKD with diffuse fibrosis. Native T1 is a non-specific readout that may also relate to increased intramyocardial fluid. We examined concomitant T1 and T2 mapping signatures and undertook comparisons with other hypertrophic conditions. METHODS: In this prospective multicentre study, consecutive CKD patients (n = 154) undergoing routine clinical cardiac magnetic resonance (CMR) imaging were compared with patients with hypertensive (HTN, n = 163) and hypertrophic cardiomyopathy (HCM, n = 158), and normotensive controls (n = 133). RESULTS: Native T1 was significantly higher in all patient groups, whereas native T2 in CKD only (p < 0.001 vs. all groups). Native T1 and T2 were interrelated in patient groups and the strength of association was condition-specific (CKD r = 0.558, HTN r = 0.324, both p < 0.001; HCM r = 0.157, p = 0.05). Native T1 and T2 were similarly correlated in all CKD stages (S3 r = 0.501, S4 0.586, S5 r = 0.424, p < 0.001 for all). Native T1 was the strongest myocardial discriminator between patients and controls (area under the curve, AUC HCM: 0.97; CKD: 0.97, HTN 0.98), native T2 between CKD vs HCM (AUC 0.90) and native T1 and T2 between CKD vs HTN (AUC: 0.83 and 0.80 respectively), p < 0.001 for all. CONCLUSIONS: Our findings reveal different CMR signatures of common hypertrophic cardiac phenotypes. Native T1 was raised in all conditions, indicating the presence of pathologic hypertrophic remodelling. Markedly raised native T2 was CKD-specific, suggesting a prominent role of intramyocardial fluid.

Aortic stiffness is independently associated with interstitial myocardial fibrosis by native T1 and accelerated in the presence of chronic kidney disease.

BACKGROUND: Patients with chronic kidney disease (CKD) have considerable cardiovascular morbidity and mortality. Aortic stiffness is an independent predictor of cardiovascular risk and related to left ventricular remodeling and heart failure. Myocardial fibrosis is the pathophysiological hallmark of the failing heart. METHODS AND RESULTS: An observational study of consecutive CKD patients (n = 276) undergoing comprehensive clinical cardiovascular magnetic resonance imaging. The relationship between aortic stiffness, myocardial fibrosis, left ventricular remodeling and the severity of chronic kidney disease was examined. Compared to age-gender matched controls with no known kidney disease (n = 242), CKD patients had considerably higher myocardial native T1 and central aortic PWV (p ≪ 0.001), as well as abnormal diastolic relaxation by E/e' (mean) by echocardiography (p ≪ 0.01). A third of all patients had LGE, with similar proportions for the presence and the (ischaemic and non-ischaemic) pattern between the groups. PWV was strongly associated with and age, NT-proBNP and native T1 in both groups, but not with LGE presence or type; the associations were amplified in severe CKD stages. In multivariate analyses, PWV was independently associated with native T1 in both groups (p ≪ 0.01) with near two-fold increase in adjusted R2 in the presence of CKD (native T1 (10 ms) R2, B(95%CI) CKD vs. non-CKD 0.28, 0.2(0.15-0.25) vs. 0.18, 0.1(0.06-0.15), p ≪ 0.01). CONCLUSIONS: Aortic stiffness and interstitial myocardial fibrosis are interrelated; this association is accelerated in the presence of CKD, but independent of LGE. Our findings reiterate the significant contribution of CKD-related factors to the pathophysiology of cardiovascular remodeling.

CMR imaging biosignature of cardiac involvement due to cancer-related treatment by T1 and T2 mapping.

BACKGROUND: Cancer-related treatment is associated with development of heart failure and poor outcome in cancer-survivors. T1 and T2 mapping by cardiovascular magnetic resonance (CMR) may detect myocardial injury due to cancer-related treatment. METHODS: Patients receiving cancer-related treatment regimes underwent screening of cardiac involvement with CMR, either within 3 months (early Tx) or >12 months (late Tx) post-treatment. T1 and T2 mapping, cardiac function, strain, ischaemia-testing, scar-imaging and serological cardiac biomarkers were obtained. RESULTS: Compared to age/gender matched controls (n = 57), patients (n = 115, age (yrs): median(IQR) 48(28-60), females, n = 60(52%) had reduced left ventricular ejection fraction (LV-EF) and strain, and higher native T1 and T2. The early Tx group (n = 52) had significantly higher native T1, T2 and troponin levels compared to the late Tx group, indicating myocardial inflammation and oedema (p < 0.01). On the contrary, late Tx patients showed raised native T1, increased LV-end-systolic volumes, reduced LV-EF and deformation, and elevated NT-proBNP, suggesting myocardial fibrosis and remodelling (p < 0.05). Prospective validation of these results in an independent cohort of patients with similar treatment regimens (n = 25) and longitudinal assessments revealed high concordance of CMR imaging signatures of early and late cardiac involvement. CONCLUSIONS: Native T1 and T2 mapping can be valuable in detecting and monitoring of cardiac involvement with cancer-related treatment, providing distinct biosignatures of early inflammatory involvement (raised native T1 and T2) and interstitial fibrosis and remodelling (raised native T1 but not T2), respectively. Our findings may provide an algorithm allowing to identify susceptible myocardium to potentially guide cardio-protective treatment measures.