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Background: Left ventricular (LV) circumferential and longitudinal strain provide important insight into LV mechanics and function, each contributing to volumetric changes throughout the cardiac cycle. We sought to explore this strain-volume relationship in more detail, by mathematically integrating circumferential and longitudinal strain and strain rate to predict LV volume and volumetric rates of change. Methods: Cardiac magnetic resonance (CMR) imaging from 229 participants from the Alberta HEART Study (46 healthy controls, 77 individuals at risk for developing heart failure [HF], 70 patients with diagnosed HF with preserved ejection fraction [HFpEF], and 36 patients with diagnosed HF with reduced ejection fraction [HFrEF]) were evaluated. LV volume was assessed by the method of disks and strain/strain rate were assessed by CMR feature tracking. Results: Integrating endocardial circumferential and longitudinal strain provided a close approximation of LV ejection fraction (EFStrain), when compared to gold-standard volumetric assessment (EFVolume: r = 0.94, P < 0.0001). Likewise, integrating circumferential and longitudinal strain rate provided a close approximation of peak ejection and peak filling rates (PERStrain and PFRStrain, respectively) compared to their gold-standard volume-time equivalents (PERVolume, r = 0.73, P < 0.0001 and PFRVolume, r = 0.78, P < 0.0001, respectively). Moreover, each integrated strain measure differentiated patients across the HF continuum (all P < 0.01), with the HFrEF group having worse EFStrain, PERStrain, and PFRStrain compared to all other groups, and HFpEF having less favorable EFStrain and PFRStrain compared to both at-risk and control groups. Conclusions: The data herein establish the theoretical framework for integrating discrete strain components into volumetric measurements across the cardiac cycle, and highlight the potential benefit of this approach for differentiating patients along the heart failure continuum. [ABSTRACT FROM AUTHOR]

Background: Rehospitalizations within 7 days after discharge may reflect the quality of hospital care. Objective: We examined factors associated with 7-day readmissions after discharge for heart failure (HF). Methods: Using a matched pair case-control design, we examined health records for sociodemographic, clinical, and health system factors for patients with a primary diagnosis of HF (ICD-10 I50) discharged alive from all acute care hospitals in Calgary, Alberta, from 2004 to 2012. Logistic regression was used to identify variables associated with 7-day all-cause readmission. Results: We included 382 patients, or 191 in matched pairs, with 41% of readmissions due to HF. Frailty (adjusted odds ratio [aOR], 2.30; 95% confidence interval [CI], 1.41-3.76) and attending physician as specialist (aOR, 2.10; 95% CI, 1.32-3.42) were associated with increased likelihood of readmission. Reduced likelihood of readmission was associated with documented instructions for follow-up with a family physician within 1 week of discharge (aOR, 0.56; 95% CI, 0.36-0.88). All 3 factors were easily abstracted from all patient records, including frailty, which was defined as all 3 of age older than 75 years, 3 or more comorbid conditions, and requiring assistance with activities of daily living. Conclusion: Very early readmission to hospital after HF admission is associated with 3 factors that may be easily identified in patient records. [ABSTRACT FROM AUTHOR]