N-terminal pro-brain natriuretic peptide in relation to inflammation, myocardial necrosis, and the effect of an invasive strategy in unstable coronary artery disease

OBJECTIVES: We sought to examine whether measurements of N-terminal pro-brain natriuretic peptide (NT-proBNP), in addition to cardiac troponin T (cTnT) and interleukin-6 (IL-6), improve the ability to identify high-risk patients who benefit from an early invasive strategy. BACKGROUND: Biochemical indicators of cardiac performance (e.g., NT-proBNP), inflammation (e.g., IL-6), and myocardial damage (e.g., cTnT) predict mortality in unstable coronary artery disease (UCAD) (i.e., unstable angina or non-ST-segment elevation myocardial infarction [MI]). In these patients, an early invasive treatment strategy improves the outcome. METHODS: Levels of NT-proBNP, cTnT, and IL-6 were measured in 2,019 patients with UCAD randomized to an invasive or non-invasive strategy in the FRagmin and fast revascularization during InStability in Coronary artery disease (FRISC-II) trial. Patients were followed up for two years to determine death and MI. RESULTS: Patients in the third NT-proBNP tertile had a 4.1-fold (95% confidence interval [CI] 2.4 to 7.2) and 3.5-fold (95% CI 1.8 to 6.8) increased mortality in the non-invasive and invasive groups, respectively. An increased NT-proBNP level was independently associated with mortality. In patients with increased levels of both NT-proBNP and IL-6, an early invasive strategy reduced mortality by 7.3% (risk ratio 0.46, 95% CI 0.21 to 1.00). In patients with lower NT-proBNP or IL-6 levels, the mortality was not reduced. Only elevated cTnT was independently associated with future MI and a reduction of MI by means of an invasive strategy. CONCLUSIONS: N-terminal proBNP is independently associated with mortality. The combination of NT-proBNP and IL-6 seems to be a useful tool in the identification of patients with a definite survival benefit from an early invasive strategy. Only cTnT is independently associated with future MI and a reduction of MI by an invasive strategy.     

Repeat surgery without preoperative angiography in limbs with patent infrainguinal bypass grafts

The aim of this study was to assess the feasibility and results of repeat surgery without preoperative angiography in limbs with patent infrainguinal bypass grafts. Between January 1995 and December 1999, 73 surgical interventions were performed for correction of inflow, graft, or runoff-related lesions in limbs with patent infrainguinal bypass grafts. Fifty-six of the 73 cases were operated on based on the findings obtained from duplex scanning alone. There were 53 vein and 3 prosthetic grafts in the series. The indications for intervention without angiography were stenotic or occlusive lesions in 35, graft aneurysm in 7, and arteriovenous fistulae in 14. There were no deviations from the preoperatively planned surgical strategy in patients undergoing surgery without preoperative angiography. Cumulative life table primary, (stenosis free) and primary-assisted patency rates, at 12 months following graft revisions (excluding arteriovenous fistulae ligatures) without preoperative angiography, were 64% and 85%, respectively. The corresponding figures for revisions performed with preoperative angiography were 58% and 84%, respectively. There were no significant differences between patients undergoing surgery with or without preoperative diagnostic angiography with regard to patency rates. Surgical interventions for correction of infrainguinal graft-related stenotic or aneurysmal lesions can be safely performed based on findings obtained from duplex scanning.