David Burgess

BACKGROUND: The prognostic role of brain natriuretic peptide (BNP) measurement before noncardiac surgery is unclear. The authors therefore performed a meta-analysis of studies in patients undergoing noncardiac surgery to assess the prognostic value of elevated BNP or N-terminal pro-BNP (NT-proBNP) levels in predicting mortality and major adverse cardiovascular events (MACE) (cardiac death or nonfatal myocardial infarction). METHODS: Unrestricted searches of MEDLINE and EMBASE bibliographic databases were performed using the terms "brain natriuretic peptide," "b-type natriuretic peptide," "BNP," "NT-proBNP," and "surgery." In addition, review articles, bibliographies, and abstracts of scientific meetings were manually searched. The meta-analysis included prospective studies that reported on the association of BNP or NT-proBNP and postoperative major adverse cardiovascular event (MACE) or mortality. The study endpoints were MACE, all-cause mortality, and cardiac mortality at short-term (less than 43 days after surgery) and longer-term (more than 6 months) follow-up. A random-effects model was used to pool study results; funnel-plot inspection was done to evaluate publication bias; Cochrane chi-square test and I testing was used to test for heterogeneity. RESULTS: Data from 15 publications (4,856 patients) were included in the analysis. Preoperative BNP elevation was associated with an increased risk of short-term MACE (OR 19.77; 95% confidence interval [CI] 13.18-29.65; P < 0.0001), all-cause mortality (OR 9.28; 95% CI 3.51-24.56; P < 0.0001), and cardiac death (OR 23.88; 95% CI 9.43-60.43; P < 0.00001). Results were consistent for both BNP and NT-proBNP. Preoperative BNP elevation was also associated with an increased risk of long-term MACE (OR 17.70; 95% CI 3.11-100.80; P < 0.0001) and all-cause mortality (OR 4.77; 95% CI 2.99-7.46; P < 0.00001). CONCLUSIONS: Elevated BNP and NT-proBNP levels identify patients undergoing major noncardiac surgery at high risk of cardiac mortality, all-cause mortality, and MACE.

BACKGROUND: Endovascular treatment of autogenous arteriovenous haemodialysis fistula stenosis has high reintervention rates. We investigate the effect of drug-eluting balloons in the treatment of recurrent haemodialysis fistula stenosis. METHODS: This is a randomised, controlled, investigator-initiated and run, prospective, blinded, multicentre trial. Patients with recurrent autogenous arteriovenous haemodialysis fistula stenosis received standard endovascular treatment plus drug-eluting balloon or standard endovascular treatment plus uncoated balloon (Sham). Primary endpoint was late lumen loss in trial area on ultrasound at 6 weeks, 3, 6 and 12 months. Secondary endpoints were freedom from reintervention to the Index Trial Area and decline in fistula flow (Qa). Interim analysis was performed at 6 months (unblinded due to timeliness). RESULTS: Patients with 132 recurrent stenoses (48% in bare Nitinol stents) were randomised with 70 receiving drug-eluting balloon and 62 Sham. At 6 months, decline in late lumen loss was 0.23 ± 0.03 mm/month for Sham and 0.045 ± 0.03 mm/month for drug-eluting balloon arm, a significant difference (0.18 mm, p = 0.0002). At 12 months, this difference persisted at 0.12 mm (p = 0.0003). At 6 months, significant difference in late lumen loss for instent restenoses (p = 0.0004) was observed, with non-significant difference for unstented restenoses (p = 0.065). Mean time for freedom from reintervention was 10.14 months for Sham versus 42.39 months for drug-eluting balloon (p = 0.001). The same was shown for instent (p = 0.014) and unstented (p = 0.029) restenoses. Qa decline rate at 6 months was 36.89 mL/min/month (Sham) and 0.41 mL/min (drug-eluting balloon). The difference was significant (36.48 mL/min; p = 0.02) and persisted to 12 months (p = 0.44). CONCLUSION: Paclitaxel drug-eluting balloon significantly delays restenosis after angioplasty for recurrent autogenous arteriovenous haemodialysis fistula stenosis, persisting to 12 months. Drug-eluting balloon significantly increases freedom from reintervention at 12 months with these effects true in stented and unstented fistulas.