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Abstract
Background Impaired myocardial perfusion reserve has been demonstrated in non-ischemic dilated cardiomyopathy (NIDCM) by positron emission tomography (PET) and adenosine-stress first-pass perfusion cardiac magnetic resonance (CMR) imaging. Adenosine stress native T1 mapping is a novel CMR technique able to assess myocardial perfusion without the use of contrast agents. Aim of the present study was to the determine the clinical utility of this novel CMR technique in NIDCM.
Methods A total of 20 consecutive patients (mean age 61±12 years, 80% males) with diagnosis of NIDCM who consented to be enrolled in the UHSM CMR registry were included in the present study. CMR at 3T including 1. cine imaging for the assessment of LV volumes, mass and global longitudinal strain (GLS) by tissue-tracking imaging; 2. rest and stress (adenosine 140 mcg/kg/min) MOLLI T1 mapping of mid ventricular slice for the assessment of rest and stress T1 values and T1 reactivity (ΔT1%); 3. first-pass perfusion imaging for the assessment of myocardial perfusion reserve index (MPRI) and 4. late gadolinium enhancement (LGE) imaging for the assessment of myocardial replacement fibrosis, was performed. Twenty control patients without history of known coronary artery disease and evidence of reversible ischemia or previous myocardial infarct on CMR imaging were included for comparison purposes.
Results NIDCM patients had significantly higher native T1 value (1263±47 ms vs. 1234±38 ms, p=0.031), significantly lower ΔT1% (3.2%±1.5% vs. 5.7±1.7%, p<0.001, figure 1A), significantly lower MPRI (1.32±0.18 vs. 1.67±0.13, p<0.001) and significantly lower GLS (−10±4% vs. −16±2%, p<0.001) as compared to controls. A significant strong relation between ΔT1% and MPRI (ß=0.76, p<0.001, figure 1B) and a significant moderate relation between DT1% and GLS (ß=−0.54, p<0.001) were observed.
Conclusion T1 reactivity, myocardial perfusion reserve and GLS are significantly reduced in NIDCM patients compared to controls. Adenosine stress T1 mapping holds promise for detection of impaired myocardial perfusion reserve in NIDCM without requirement for contrast agents.