DSPECT-specific normative limits for left ventricular size and function.

BACKGROUND: Differences in spatial resolution and image filtering between the solid-state DSPECT and traditional Anger SPECT (ASPECT) cameras are likely to result in differences in LV measurements. However, DSPECT-specific normal values are not available. The traditional approach of using patients deemed to have a low (< 5%) probability of coronary artery disease for the derivation of normative values has a number of limitations. We used healthy organ-donor subjects without known disease or medication use for derivation of normal values. METHODS: Subjects were 92 consecutive kidney or liver donors who underwent single-day rest (5 mCi)-stress (15 mCi) Tc-99m sestamibi-gated SPECT myocardial perfusion imaging (MPI) on the DSPECT camera for pre-operative evaluation and had normal perfusion and LV function. Exclusion criteria included any known cardiac disease or medications. LV measurements were made on the post-stress supine stress images using QGS®. RESULTS: Of 92 subjects (mean age 54.4 ± 15.0 and 39% men), mean EF ± 2SD for women and men was 77.2% ± 14.1% and 70.0 % ± 14.7%, respectively. Mean end-diastolic volume ± 2SD for women and men was 67.0 ± 32.2 mL and 99.6 ± 51.6 mL (indexed 38.3 ± 17.2 mL/m2 and 48.1 ± 25.9 mL/m2), respectively. Mean end-systolic volume ± 2SD for women and men was 16.1 ± 15.7 mL and 31.2 ± 29.2 mL (indexed 9.2 ± 8.8 mL/m2 and 15.0 ± 14.2 mL/m2), respectively. Mean LV wall volume ± 2SD for women and men was 95.9 ± 26.0 mL and 112.0 ± 48.8 mL (indexed 55.0 ± 13.8 mL/m2 and 54.1 ± 24.6 mL/m2), respectively. CONCLUSION: We report DSPECT-specific LV measurements from normal subjects from which limits of normality can be derived for clinic use. Organ donors who undergo pre-operative MPI are a suitable cohort for the derivation of normal values.

Increased Mortality in Patients With Preoperative and Persistent Postoperative Pulmonary Hypertension Undergoing Mitral Valve Surgery for Mitral Regurgitation: A Cohort Study.

Background Preoperative pulmonary hypertension (PH) is associated with excess mortality among patients with severe mitral regurgitation undergoing mitral valve surgery (MVS). However, the links between PH phenotype, pulmonary vascular remodeling, and persistent postoperative PH are not well understood. We aimed to describe the associations between components of pulmonary hemodynamics as well as postoperative residual PH with longitudinal mortality in patients with severe mitral regurgitation who received MVS. Methods and Results Patients undergoing MVS for severe mitral regurgitation from 2011 to 2016 were retrospectively identified within our health system (n=488). Mean pulmonary artery pressure and other hemodynamic variables were determined by presurgical right-heart catheterization. Postoperative pulmonary artery systolic pressure was assessed on echocardiogram 42 to 365 days post-MVS. Longitudinal survival over a mean 3.9 years of follow-up was evaluated using Cox proportional hazards modeling to compare survival after adjustment for demographics, surgical characteristics, and comorbidities. Pre-MVS prevalence of PH was high at 85%. After adjustment, each 10-mm Hg increase in preoperative mean pulmonary artery pressure was associated with a 1.38-fold increase in risk of death (95% CI, 1.13-1.68). Elevated preoperative pulmonary vascular resistance, transpulmonary gradient, and right atrial pressure were similarly associated with increased mortality. Among 231 patients with postoperative echocardiogram, evidence of PH on echocardiogram (pulmonary artery systolic pressure ≥35 mm Hg) was associated with increased risk of death (hazard ratio [HR], 2.02 [95% CI, 1.17-3.47]); however, this was no longer statistically significant after adjustment (HR, 1.55 [95% CI, 0.85-2.85]). Conclusions In patients undergoing MVS for mitral regurgitation, preoperative PH, and postoperative PH were associated with increased mortality.