The strain relaxation index derived from tagged MRI significantly predicted combined heart failure and atrial fibrillation over an 8-year follow-up (IDI 1.5%, P<0.05; NRI 11.4%, P<0.05).
Cohort (n=1,544)
Yes
Does the strain relaxation index (SRI) derived from tagged MRI predict incident heart failure and atrial fibrillation in a population free of known cardiovascular disease?
The strain relaxation index (SRI) derived from tagged MRI independently predicts incident heart failure and atrial fibrillation over 8 years in individuals without known cardiovascular disease, improving risk reclassification over conventional indices.
p-value: p=<0.05
OBJECTIVES: The strain relaxation index (SRI), a novel diastolic functional parameter derived from tagged magnetic resonance imaging (MRI), is used to assess myocardial deformation during left ventricular relaxation. We investigated whether diastolic function indexed by SRI predicts heart failure (HF) and atrial fibrillation (AF) over an 8-year follow-up. METHODS: As a part of the multi-ethnic study of atherosclerosis, 1544 participants free of known cardiovascular disease (CVD) underwent tagged MRI in 2000-02. Harmonic phase analysis was used to compute circumferential strain. Standard parameters, early diastolic strain rate (EDSR) and the peak torsion recoil rate were calculated. An SRI was calculated as difference between post-systolic and systolic times of the strain peaks, divided by the EDSR peak. It was normalized by the total interval of relaxation. Over an 8-year follow-up period, we defined AF (n = 57) or HF (n = 36) as combined (n = 80) end-points. Cox regression assessed the ability of SRI to predict events adjusted for risk factors and markers of subclinical disease. Integrated discrimination index (IDI) and net reclassification index (NRI) of SRI, compared with conventional indices, were also assessed. RESULTS: The hazard ratio for SRI remained significant for the combined HF and AF end-points as well as for HF alone after adjustment. For the combined end-point, IDI was 1.5% (P < 0.05) and NRI was 11.4% (P < 0.05) for SRI. Finally, SRI was more robust than all other existing cardiovascular magnetic resonance diastolic functional parameters. CONCLUSION: SRI predicts HF and AF over an 8-year follow-up period in a large population free of known CVD, independent of established risk factors and markers of subclinical CVD.
Ambale‐Venkatesh et al. (Sun,) conducted a cohort in Free of known cardiovascular disease (n=1,544). Strain relaxation index (SRI) derived from tagged MRI vs. Conventional indices was evaluated on Combined heart failure (HF) and atrial fibrillation (AF) (p=<0.05). The strain relaxation index derived from tagged MRI significantly predicted combined heart failure and atrial fibrillation over an 8-year follow-up (IDI 1.5%, P<0.05; NRI 11.4%, P<0.05).