Reappraisal of Atrial fibrillation: interaction between hyperCoagulability, Electrical remodelling and Vascular destabilisation in the progression of AF (RACE V) Tissue Bank Project: study design

Determinants and impact of postoperative atrial fibrillation burden during 2.5 years of continuous rhythm monitoring after cardiac surgery: Results from the RACE V prospective cohort study

BACKGROUND

Early postoperative atrial fibrillation (POAF) is common after cardiac surgery and is associated with late-POAF recurrences. However, little is known about the burden of POAF and its potential impact on long-term outcomes after cardiac surgery, particularly on the risk for late-POAF recurrences.

OBJECTIVE

The purpose of this study was to establish the distribution of POAF burden and to determine the association between early-POAF burden and late-POAF recurrences during 2.5 years of continuous rhythm monitoring after cardiac surgery in patients with and without preoperative history of atrial fibrillation (AF).

METHODS

Patients undergoing cardiac surgery were prospectively enrolled and postoperatively continuously monitored with an implantable loop recorder for 2.5 years. All patients underwent extensive clinical assessment at baseline. During follow-up, all AF episodes were registered, and AF associated metrics, such as burden, were calculated for different time intervals. Early-POAF was defined as AF within first 90 postoperative days and late-POAF as AF after this interval.

RESULTS

A total of 98 consecutive patients were included. POAF burden during the early postoperative phase was significantly higher compared to the late postoperative phase (P <.001). The longest individual POAF episode was strongly associated with increased POAF burden after adjusting for age, sex, and AF history (standardized Beta: 0.91, P <.001). Also, early-POAF burden was associated with late-POAF (re)occurrence after adjusting for age, sex, AF history (adjusted hazard ratio 1.93, 95% confidence interval 1.42-2.62, P <.001).

CONCLUSION

POAF burden was significantly associated with the longest individual POAF episode duration. Additionally, greater early-POAF burden was associated with increased late-POAF incidence, highlighting its potential in estimating the risk for long-term POAF recurrences.

Circulating BMP10 Levels Associate With Late Postoperative Atrial Fibrillation and Left Atrial Endomysial Fibrosis

BACKGROUND

Serum bone morphogenetic protein 10 (BMP10) blood levels are a marker for history of atrial fibrillation (AF) and for major adverse cardiovascular events in patients with AF, including stroke, AF recurrences after catheter ablations, and mortality. The predictive value of BMP10 in patients undergoing cardiac surgery and association with morphologic properties of atrial tissues are unknown.

OBJECTIVES

This study sought to study the correlation between BMP10 levels and preoperative clinical traits, occurrence of early and late postoperative atrial fibrillation (POAF), and atrial fibrosis in patients undergoing cardiac surgery.

METHODS

Patients with and without preoperative AF history undergoing first cardiac surgery were included (RACE V, n = 147). Preoperative blood biomarkers were analyzed, left (n = 114) and right (n = 125) atrial appendage biopsy specimens were histologically investigated after WGA staining, and postoperative rhythm was monitored continuously with implantable loop recorders (n = 133, 2.5 years).

RESULTS

Adjusted multinomial logistic regression indicated that BMP10 accurately reflected a history of persistent AF (OR: 1.24, 95% CI: 1.10-1.40, P = 0.001), similar to NT-pro-BNP. BMP10 levels were associated with increased late POAF90 occurrence after adjustment for age, sex, AF history, and early POAF occurrence (HR: 1.07 [per 0.1 ng/mL increase], 95% CI: 1.00-1.14, P = 0.041). Left atrial endomysial fibrosis (standardized β = 0.22, P = 0.041) but not overall fibrosis (standardized Β = 0.12, P = 0.261) correlated with circulating BMP10 after adjustment for age, sex, AF history, reduced LVF, and valvular surgery indication.

CONCLUSIONS

Increased BMP10 levels were associated with persistent AF history, increased late POAF incidence, and LAA endomysial fibrosis in a diverse sample of patients undergoing cardiac surgery.

Clinical Predictors of Device-Detected Atrial Fibrillation During 2.5 Years After Cardiac Surgery: Prospective RACE V Cohort

BACKGROUND

Postoperative atrial fibrillation (POAF) is a frequent complication after cardiac surgery that is associated with late atrial fibrillation (AF) recurrences (late-POAF) and increased morbidity and long-term mortality.

OBJECTIVES

This study sought to determine device-detected POAF incidence and to identify clinical variables associated with POAF, both in patients with and without preoperative AF history.

METHODS

A total of 133 consecutive patients undergoing cardiac surgery were prospectively enrolled and continuously monitored with an implantable loop recorder for 2.5 years after surgery. Preoperative transthoracic echocardiography, 12-lead electrocardiogram, blood biomarkers, and clinical data were analyzed to develop prediction models for early- and late-POAF.

RESULTS

In patients without preoperative AF history, early-POAF within the first 90 postoperative days occurred in 41 (47.1%) of 87 patients. Late-POAF after the first 90 postoperative days occurred in 22 (25%) of 87 patients, and 20 of these patients also had early-POAF during the first 90 days (20 of 22 [91%]). Increased right atrial minimum volume indexed for body surface area (RAVImin) and early-POAF were independently associated with late-POAF. A prediction model for late-POAF, which included RAVImin >11 mL/m2, age >65 years, and early-POAF, achieved an area under the curve of 0.82 (95% CI: 0.72-0.92). For patients with preoperative AF-history, late-POAF recurrences were frequent (22 of 33 [67%]). Increased RAVImin was independently associated with a higher incidence of late-POAF.

CONCLUSIONS

In patients with and without AF history, late-POAF recurrences are frequent, including in patients undergoing surgical AF ablation. In patients with no history of AF, late-POAF might be predicted with excellent accuracy by using a combination of preoperative variables. In patients with a history of AF, signs of advanced AF substrate (eg, increased right atrial volumes) were associated with long-term AF recurrences. [Reappraisal of Atrial Fibrillation: Interaction Between Hypercoagulability, Electrical Remodeling, and Vascular Destabilisation in the Progression of AF; NCT03124576].