High-sensitivity troponin I in persistent atrial fibrillation - relation to NT-proBNP and markers of inflammation and haemostasis.

PURPOSE: As cardiac troponins emerge as prognostic markers in atrial fibrillation (AF), it is important to identify mechanisms initiating and perpetuating cardiac troponin release, including its relations to other circulating biomarkers, in AF populations. We studied associations between high-sensitivity troponin I (hs-TnI) and markers representing myocardial wall tension, inflammation and haemostasis in persistent AF. METHODS: In a double blind, placebo-controlled study, 171 patients referred for electrical cardioversion for persistent AF were randomised to receive candesartan or placebo for 3-6 weeks before and 6 months after cardioversion. Associations between baseline levels of hs-TnI and other biomarkers were investigated by bivariate non-parametric correlations (Spearman's correlation coefficient denoted rs). RESULTS: Baseline levels of hs-TnI correlated significantly, although weakly, with interleukin-6 (rs = 0.260, p = .003), N-terminal pro-B-type natriuretic peptide (rs = 0.251, p = .004), tissue-plasminogen activator antigen (rs = 0.233, p = .008), D-dimer (rs = 0.220, p = .013), E-selectin (rs = 0.207, p = .019), high-sensitivity C-reactive protein (rs = 0.202, p = .022) and vascular cell adhesion molecule-1 (rs = 0.189, p = .032). CONCLUSIONS: Hs-TnI correlated weakly with biomarkers representing myocardial wall tension, inflammation and haemostasis in persistent AF. The lack of any strong correlation between hs-TnI and the investigated biomarkers is in concert with the idea that hs-TnI release is an independent process parallel to other pathophysiological mechanisms associated with AF.

Effect of sinus rhythm restoration on markers of thrombin generation in atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) confers a hypercoagulable state; however, it is not clear whether restoration of sinus rhythm is associated with normalisation of markers of thrombogenesis. We studied the impact of sustained sinus rhythm on prothrombotic markers, and their predictive abilities in foreseeing rhythm outcome after cardioversion. METHODS: In a double blind, placebo-controlled study, 171 patients referred for electrical cardioversion of persistent AF were randomised to receive candesartan or placebo for 3-6 weeks before and 6 months after cardioversion. Endogenous thrombin potential (ETP), prothrombin fragment 1 + 2 (F1 + 2) and D-dimer were measured before cardioversion and at end of study. These markers were also measured in a reference group comprising 49 subjects without AF. RESULTS: The markers remained unchanged in those 28 patients who maintained sinus rhythm. Discontinuation of warfarin treatment in a subset of 13 low-risk patients in sinus rhythm was associated with significantly higher levels of D-dimer and F1 + 2 compared to the reference group; D-dimer (456 ng/mL (276, 763) vs. 279 ng/mL (192, 348), p = 0.002) and F1 + 2 (700 pmol/L (345, 845) vs. 232 pmol/L (190, 281), p < 0.001). None of the markers were associated with rhythm outcome after electrical cardioversion. CONCLUSIONS: Sustained sinus rhythm for 6 months after cardioversion for AF had no impact on ETP, F1 + 2 or D-dimer levels. Discontinuation of warfarin in low-risk patients with sustained sinus rhythm was associated with significantly higher levels of D-dimer and F1 + 2 compared to the reference group. Our results suggest persistent hypercoagulability in AF patients despite long-term maintenance of sinus rhythm. TRIAL REGISTRATION: The CAPRAF study was registered at clinicaltrials.gov (NCT00130975) in August 2005.

High-Sensitivity Troponin I and Rhythm Outcome after Electrical Cardioversion for Persistent Atrial Fibrillation.

OBJECTIVES: We hypothesised that high-sensitivity troponin I (hs-TnI) might predict long-term rhythm outcome after cardioversion for persistent atrial fibrillation (AF), and that maintenance of sinus rhythm and/or treatment with the angiotensin II type 1 receptor blocker candesartan would reduce hs-TnI levels. METHODS: In a double-blind, placebo-controlled study, 171 patients referred for electrical cardioversion for AF were randomised to receive candesartan or placebo for 3-6 weeks before cardioversion and for 6 months after electrical cardioversion. Blood samples for analysis of hs-TnI (Abbott Diagnostics) were available in 129 patients at baseline and in 60 successfully cardioverted patients at study end. RESULTS: Hs-TnI was detectable in all subjects, with a median value of 5.3 ng/l (25th percentile 3.7, 75th percentile 7.2). hs-TnI at baseline was not predictive of rhythm outcome 6 months after electrical cardioversion for persistent AF. Treatment with candesartan did not influence the levels of hs-TnI. hs-TnI was unchanged from baseline to study end in patients who maintained sinus rhythm [4.9 (3.7, 7.0) and 5.0 (4.0, 6.4) ng/l, respectively; p = 0.699). CONCLUSIONS: hs-TnI did not predict AF recurrence after cardioversion. hs-TnI levels were unchanged in patients maintaining sinus rhythm for 6 months after electrical cardioversion. hs-TnI levels were not influenced by treatment with candesartan.

Troponin I levels in permanent atrial fibrillation-impact of rate control and exercise testing.

BACKGROUND: High-sensitivity troponin I (hs-TnI) and troponin T (hs-TnT) are moderately correlated and independently related to outcome in atrial fibrillation (AF). Rate controlling therapy has been shown to reduce hs-TnT, however the potential impact on hs-TnI levels, and whether this differs from the effects on hs-TnT, has not been investigated previously. METHODS: Sixty patients with stable, permanent AF without heart failure or known ischemic heart disease were included in a randomised crossover study (mean age 71 ± 9 years, 18 women). Diltiazem 360 mg, verapamil 240 mg, metoprolol 100 mg, and carvedilol 25 mg were administered once daily for three weeks, in a randomised sequence. At baseline and on the last day of each treatment period, hs-TnI was measured at rest and after a maximal exercise test and compared to hs-TnT. RESULTS: Hs-TnI and hs-TnT correlated moderately at baseline (rs = 0.582, p < 0.001). All drugs reduced both the resting and the peak exercise levels of hs-TnI compared with baseline (p < 0.001 for all). The decline in resting hs-TnI and hs-TnT values relative to baseline levels was similar for all drugs except for verapamil, which reduced hs-TnI more than hs-TnT (p = 0.017). Levels of hs-TnI increased significantly in response to exercise testing at baseline and at all treatment regimens (p < 0.001 for all). The relative exercise-induced increase in hs-TnI was significantly larger compared to hs-TnT at baseline (p < 0.001), on diltiazem (p < 0.001) and on verapamil (p = 0.001). CONCLUSIONS: In our population of stable, permanent AF patients, all four rate control drug regimens reduced hs-TnI significantly, both at rest and during exercise. The decline in hs-TnI and hs-TnT levels associated with beta-blocker and calcium channel blocker treatment was similar, except for a larger relative decrease in hs-TnI levels following verapamil treatment. TRIAL REGISTRATION: www.clinicaltrials.gov ( NCT00313157 ).

Pediatric cardiac surgery in Northern Russia. Results from an international cooperative program.

OBJECTIVES: In order to evaluate a Norwegian-Russian clinical cooperation, this study sought to compare the incidence, early mortality and morbidity of surgically treated patients with atrial septum defect (ASD), ventricular septum defect (VSD) and Tetralogy of Fallot (TOF) in Norway and Archangels region in Russia. DESIGN: A retrospective analysis of patient records of all those surgically treated for ASD, VSD and TOF in Norway and from Archangels region from 1 January 2000 to 31 December 2005. RESULTS: The Norwegian cohort consisted of 191 ASDs, 227 VSDs and 126 TOFs. The Russian cohort counted 128 ASDs, 77 VSDs and nine TOFs. Thirty-days mortality was 0.4% in the Norwegian VSD, 1.6% in the Norwegian TOF and 1.3% in the Russian VSD cohort. Postoperative complications in the Norwegian cohorts were 18.3% (ASDs), 15.9% (VSDs) and 34.1% (TOFs). The corresponding findings in Archangels were 4.7%, 11.7% and 0%. CONCLUSION: Surgery for ASDs, VSDs and TOFs can be carried out with minimal early mortality in both countries. The discrepancy in early postoperative morbidity illustrates the challenges in comparative studies between different countries, cultures and health care systems. The establishment of a decentralized surgical facility has increased the access to cardiac surgery to the population in Archangels region.