Brain natriuretic peptide is not reno-protective during renal ischemia-reperfusion injury in the rat.

BACKGROUND: Acute kidney injury (AKI) occurs in 30% of patients undergoing complex cardiovascular surgery, and renal ischemia-reperfusion (I/R) injury is often a contributing factor. A recent meta-analysis observed that perioperative natriuretic peptide administration was associated with a reduction in AKI requiring dialysis in cardiovascular surgery patients. This study was designed to further clarify the potential reno-protective effect of brain natriuretic peptide (BNP) using an established rat model of renal I/R injury. METHODS: The study comprised three groups (n = 10 kidneys each): (1) control (no injury); (2) I/R injury (45 min of bilateral renal ischemia followed by 3 h of reperfusion); and (3) BNP (I/R injury plus rat-BNP pretreatment at 0.01 µg/kg/min). Glomerular filtration rate (GFR) and a biomarker of AKI, urinary neutrophil gelatinase-associated lipocalin (uNGAL), were measured at baseline and at 30 minute intervals post-ischemia. Groups were compared using two-way repeated measures analysis of variance (mean ± SD, significance P < 0.05). RESULTS: Baseline GFR measurements for control, I/R, and BNP groups were 1.07 ± 0.55, 0.88 ± 0.51, and 1.03 ± 0.59 mL/min (P = 0.90), respectively. Post-ischemia, GFR was significantly lower in I/R and BNP compared with controls at 30 min, 1.29 ± 0.97, 0.08 ± 0.04, and 0.06 ± 0.05 mL/min (P < 0.01), and remained lower through 3 h, 1.79 ± 0.44, 0.30 ± 0.17, and 0.32 ± 0.12 mL/min (P < 0.01). Comparing I/R to BNP groups, GFR did not differ significantly at any time point. There was no significant difference in uNGAL levels at 1 h (552 ± 358 versus 516 ± 259 ng/mL, P = 0.87) or 2 h (1073 ± 589 versus 989 ± 218 ng/mL, P = 0.79) between I/R and BNP. CONCLUSIONS: BNP does not reduce the renal injury biomarker, urinary NGAL, or preserve GFR in acute renal ischemia-reperfusion injury.

Early outcomes using the Florida sleeve repair for correction of aortic insufficiency due to root aneurysms.

BACKGROUND: The Florida sleeve procedure is a simplified valve-sparing technique for repair of functional type I aortic insufficiency associated with root aneurysms. Midterm outcomes are reported, including standard echocardiographic measurements. METHODS: The study included all patients undergoing the Florida sleeve procedure who had at least 2 years of postoperative echocardiographic follow-up. Data were acquired preoperatively and postoperatively at 1 week and 1, 2, and 3 years. Measurements analyzed included left ventricular end-diastolic diameter (LVEDD), left ventricular end-systolic diameter (LVESD), and degree of aortic insufficiency. RESULTS: Complete echocardiographic data for a mean 32 +/- 6.3 months after repair were available for 18 patients. Mean LVEDD decreased from 51.6 +/- 7.4 to 49.7 +/- 6.3 mm at 1 week (p = 0.05) and 47.1 +/- 6.3 mm at 1 year (p = 0.008), and remained unchanged at 47.2 +/- 6.6 and 47.1 +/- 5.0 mm at 2 and 3 years. Mean LVESD decreased from 35.2 +/- 7.6 to 32.9 +/- 7.0 mm at 1 week (p = 0.002) and 30.7 +/- 5.6 mm at 1 year (p < 0.001), and remained unchanged at 30.9 +/- 6.2 and 31.7 +/- 4.9 mm after 2 and 3 years. The mean grade of aortic insufficiency decreased from 2.61 +/- 0.78 to 1.39 +/- 0.85 mm at 1 week (p < 0.001) and remained 1.39 +/- 0.84 mm at 1 year. Aortic insufficiency increased to 1.72 +/- 0.89 (p = 0.03) at 2 years and decreased to 1.67 +/- 0.50 (p = 0.59, from 1 week postoperatively) at 3 years. CONCLUSIONS: The sustained reduction of left ventricular dimensions 3 years after operation suggests the Florida sleeve procedure is a durable valve repair. A minor increase in the degree of aortic insufficiency warrants close follow-up, but the absence of an increase of LVEDD supports continued use of the procedure in closely studied series.