The effects of saxagliptin on cardiac structure and function using cardiac MRI (SCARF)

PURPOSE

A recent large cardiovascular outcome trial in patients with type 2 diabetes (T2DM) demonstrated excess heart failure hospitalization with saxagliptin. We sought to evaluate the impact of saxagliptin on cardiac structure and function using cardiac magnetic resonance imaging (CMR) in patients with T2DM without pre-existing heart failure.

METHODS

In this prospective study, patients with T2DM without heart failure were prescribed saxagliptin as part of routine guideline-directed management. Clinical assessment, CMR imaging and biomarkers were assessed in a blinded fashion and compared following 6 months of continued treatment. The primary outcome was the change in left ventricular (LV) ejection fraction (LVEF) after 6 months of therapy. Key secondary outcomes included changes in LV and right ventricular (RV) end-diastolic volume, ventricular mass, LV global strain and cardiac biomarkers [N terminal pro B-type natriuretic peptide (NT-proBNP) and high sensitivity C-reactive protein (hsCRP)] over 6 months.

RESULTS

The cohort (n = 16) had a mean age of 59.9 years with 69% being male. The mean hemoglobin A1c (HbA1c) was 8.3%. Mean baseline LVEF was 57% ± 3.4, with no significant change over 6 months (- 0.2%, 95% CI - 2.5, 2.1, p = 0.86). Detailed CMR analyses that included LV/RV volumes, LV mass, and feature tracking-derived strain showed no significant change (all p > 0.50). NT-proBNP and hsCRP levels did not significantly change (p > 0.20).

CONCLUSIONS

In this cohort of stable ambulatory patients with T2DM without heart failure, saxagliptin treatment was not associated with adverse ventricular remodeling over 6 months as assessed using CMR and biomarkers.

The development of exploration and spontaneous alternation in hooded rat pups: effects of unusually early eyelid opening

Changes in exploratory activity and spontaneous alternation were examined across postnatal Days 8-31 in Lister hooded rat pups whose eyelids were surgically opened at 6-8 postnatal days. Compared with controls, whose eyes open naturally at 14-16 days, the treated animals showed accelerated behavioral development. Open-field activity increased more rapidly in the week following surgery, but only when all pups in the litter had their eyelids opened, and not when only half of the litter was treated. Rearing on the hind paws emerged earlier in treated animals, but grooming was unaffected. Pups having unilateral early eyelid opening made pivotal circling movements contraversive to the opened eye in an open-field arena in the early neonatal period. When tested in a T-maze, treated pups showed earlier spontaneous alternation than controls. Possible physiological systems underlying such changes are discussed. Our results show that unusually early visual stimulation has behavioral consequences, producing a brief speeding of some attentional and investigatory behaviors, though such changes may also depend upon environmental factors.