Among patients with unstable angina or myocardial infarction without ST-segment elevation, prasugrel did not significantly reduce the frequency of the primary end point, as compared with clopidogrel, and similar risks of bleeding were observed. (Funded by Eli Lilly and Daiichi Sankyo; TRILOGY ACS ClinicalTrials.gov number, NCT00699998.).
ObjectiveRight ventricular (RV) function is a major determinant of survival in patients with pulmonary arterial hypertension (PAH). Metabolic alterations may precede haemodynamic and clinical deterioration. Increased RV fluorodeoxyglucose (FDG) uptake in positron emission tomography (PET) was recently associated with progressive RV dysfunction in MRI, but the prognostic value of their combination has not been established.MethodsTwenty-six clinically stable patients with PAH (49.9±15.2 years) and 12 healthy subjects (control group, 44.7±13.5 years) had simultaneous PET/MRI scans. FDG uptake was quantified as mean standardised uptake value (SUV) for both left ventricle (LV) and RV. Mean follow-up time of this study was 14.2±7.3 months and the clinical end point was defined as death or clinical deterioration.ResultsMedian SUVRV/SUVLV ratio was 1.02 (IQR 0.42–1.21) in PAH group and 0.16 (0.13–0.25) in controls, p<0.001. In PAH group, SUVRV/SUVLV significantly correlated with RV haemodynamic deterioration. In comparison to the stable ones, 12 patients who experienced clinical end point had significantly higher baseline SUVRV/SUVLV ratio (1.21 (IQR 0.87–1.95) vs 0.53 (0.24–1.08), p=0.01) and lower RV ejection fraction (RVEF) (37.9±5.2 vs 46.8±5.7, p=0.03). Cox regression revealed that SUVRV/SUVLV ratio was significantly associated with the time to clinical end point. Kaplan-Meier analysis showed that combination of RVEF from MRI and SUVRV/SUVLV assessment may help to predict prognosis.ConclusionsIncreased RV glucose uptake in PET and decreased RVEF identify patients with PAH with worse prognosis. Combining parameters from PET and MRI may help to identify patients at higher risk who potentially benefit from therapy escalation, but this hypothesis requires prospective validation.
Background
In pulmonary arterial hypertension (PAH) increased afterload leads to adaptive processes of the right ventricle (RV) that help to maintain arterio-ventricular coupling of RV and preserve cardiac output, but with time the adaptive mechanisms fail. In this study, we propose a multimodal approach which allows to estimate prognostic value of RV coupling parameters in PAH patients.
Methods
Twenty-seven stable PAH patients (49.5 ± 15.5 years) and 12 controls underwent cardiovascular magnetic resonance (CMR). CMR feature tracking analysis was performed for RV global longitudinal strain assessment (RV GLS). RV-arterial coupling was evaluated by combination of RV GLS and three proposed surrogates of RV afterload—pulmonary artery systolic pressure (PASP), pulmonary vascular resistance (PVR) and pulmonary artery compliance (PAC). 18-FDG positron emission tomography (PET) analysis was used to assess RV glucose uptake presented as SUVRV/LV. Follow-up time of this study was 25 months and the clinical end-point was defined as death or clinical deterioration.
Results
Coupling parameters (RV GLS/PASP, RV GLS/PVR and RV GLS*PAC) significantly correlated with RV function and standardized uptake value (SUVRV/LV). Patients who experienced a clinical end-point (n = 18) had a significantly worse coupling parameters at the baseline visit. RV GLS/PASP had the highest area under curve in predicting a clinical end-point and patients with a value higher than (−)0.29%/mmHg had significantly worse prognosis. It was also a statistically significant predictor of clinical end-point in multivariate analysis (adjusted R2 = 0.68; p < 0.001).
Conclusions
Coupling parameters are linked with RV hemodynamics and glucose metabolism in PAH. Combining CMR and hemodynamic measurements offers more comprehensive assessment of RV function required for prognostication of PAH patients.
Trial Registration: NCT03688698, 09/26/2018, retrospectively registered; Protocol ID: 2017/25/N/NZ5/02689
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