Plasma B-type natriuretic peptide predicts atrial fibrillation during rehabilitation after cardiac surgery

Predicting atrial fibrillation after cardiac surgery: a scoping review of associated factors and systematic review of existing prediction models

INTRODUCTION

Postoperative atrial fibrillation (POAF) is common after cardiac surgery and associated with increased hospital length of stay, patient morbidity and mortality. We aimed to identify factors associated with POAF and evaluate the accuracy of available POAF prediction models.

METHODS

We screened articles from Ovid MEDLINE® and PubMed Central® (PMC) and included studies that evaluated risk factors associated with POAF or studies that designed or validated POAF prediction models. We only included studies in cardiac surgical patients with sample size n ⩾ 50 and a POAF outcome group ⩾20. We summarised factors that were associated with POAF and assessed prediction model performance by reviewing reported calibration and discriminative ability.

RESULTS

We reviewed 232 studies. Of these, 142 fulfilled the inclusion criteria. Age was frequently found to be associated with POAF, while most other variables showed contradictory findings, or were assessed in few studies. Overall, 15 studies specifically developed and/or validated 12 prediction models. Of these, all showed poor discrimination or absent calibration in predicting POAF in externally validated cohorts.

CONCLUSIONS

Except for age, reporting of factors associated with POAF is inconsistent and often contradictory. Prediction models have low discrimination, missing calibration statistics, are at risk of bias and show limited clinical applicability. This suggests the need for studies that prospectively collect AF relevant data in large cohorts and then proceed to validate findings in external data sets.

Preoperative n-3 polyunsatured fatty acids are associated with a decrease in the incidence of early atrial fibrillation following cardiac surgery

BACKGROUND

Atrial fibrillation (AF) after cardiac surgery is associated with increased mortality, morbidity, and expenditure. Controversial data exist on possible preventive effects of n-3 polyunsatured fatty acids (PUFAs) against postoperative AF. We investigated whether preoperative PUFA therapy is effective in reducing AF after cardiac surgery during the surgical hospitalization and/or the cardiac rehabilitation period.

METHODS

Over a 4-year period, 530 patients (363 men, 68.5%) with a mean age of 66.4 +/- 10.9 years, undergoing cardiac surgery were monitored for ''early AF'' and ''late AF'' defined as AF documented in the surgical department or during the rehabilitation program, respectively.

RESULTS

The overall incidence of early AF in the whole study sample was 44.7%, whereas late AF occurred in 14.7% patients. Patients with AF had a longer length of hospital and rehabilitation stay (10.4 +/- 9.8 vs 9.5 +/- 9.2 days, P = .025 and 24.2 +/- 15.3 vs 21.1 +/- 8.3 days, P = .008, respectively). Early AF occurred in 31.0% of the patients with preoperative PUFAs compared with 47.3% of those without them (P = .006). Conversely, late AF was not influenced by preoperative PUFA regimen (11.9% vs 15.2%, P = .43). Preoperative PUFAs were independently associated with a 46% reduction in risk of early AF development (OR 0.54, 95% CI 0.31-0.92), after propensity score analysis.

CONCLUSION

Preoperative PUFA therapy is associated with a decreased incidence of early AF after cardiac surgery but not late AF. Patients undergoing cardiac surgery may benefit from a preventive PUFA approach.

Interpretation and use of natriuretic peptides in non-congestive heart failure settings

Natriuretic peptides (NPs) have been found to be useful markers in differentiating acute dyspneic patients presenting to the emergency department (ED) and emerged as potent prognostic markers for patients with congestive heart failure (CHF). The best-established and widely used clinical application of BNP and NT-proBNP testing is for the emergent diagnosis of CHF in patients presenting with acute dyspnea. Nevertheless, elevated NPs levels can be found in many circumstances involving left ventricular (LV) dysfunction or hypertrophy; right ventricular (RV) dysfunction secondary to pulmonary diseases; cardiac inflammatory or infectious diseases; endocrinology diseases and high output status without decreased LV ejection fraction. Even in the absence of significant clinical evidence of volume overload or LV dysfunction, markedly elevated NP levels can be found in patients with multiple comorbidities with a certain degree of prognostic value. Potential clinical applications of NPs are expanded accompanied by emerging reports regarding screening the presence of secondary cardiac dysfunction; monitoring the therapeutic responses, risk stratifications and providing prognostic values in many settings. Clinicians need to have expanded knowledge regarding the interpretation of elevated NPs levels and potential clinical applications of NPs. Clinicians should recognize that currently the only reasonable application for routine practice is limited to differentiation of acute dyspnea, rule-out-diagnostic-tests, monitoring of therapeutic responses and prognosis of acute or decompensated CHF. The rationales as well the potential applications of NPs in these settings are discussed in this review article.