Outcomes in atrial fibrillation patients with and without left ventricular hypertrophy when treated with a lenient rate-control or rhythm-control strategy

Establishment and evaluation of a nomogram prediction model for risk of atrial fibrillation recurrence after the cox-maze IV procedure

The Cox-Maze IV (CMIV) procedure is the mainstay in surgical treatment of atrial fibrillation (AF), but the rate of AF recurrence after the CMIV procedure in patients with persistent AF is difficult to accurately evaluate. In this study, we aimed to develop and validate a risk prediction model of AF recurrence within 1 year after undergoing the Cox-Maze IV procedure. We retrospectively enrolled 303 consecutive patients who underwent the Cox-Maze IV procedure for persistent AF concomitant with other cardiac procedures at our institute between 2019 and 2021. A nomogram was developed using multivariate logistic regression analysis, and the concordance statistic (C-statistic) was computed. Differentiation, calibration, clinical suitability, and bootstrapping were performed to verify the model. Among the 303 patients, 71 developed recurrent AF within 1 year of CMIV. Factors predictive of postoperative AF recurrence included age, left ventricular hypertrophy (LVH), early atrial tachyarrhythmias (ATAs), and congenital heart disease surgery (namely, ventricular septal defect repair and atrial septal defect repair). Based on the training dataset, the nomogram had a C-statistic of 0.864 (95% CI 0.811-0.918) for predicting AF recurrence. According to the receiver operating characteristic curve, (ROC curve), the cutoff value of the model was 0.293, and the specificity and sensitivity were 0.841 and 0.789, respectively. This model can predict the risk of AF recurrence after the CMIV procedure. Its discrimination, calibration, and clinical applicability are strong, and its clinical application is simple and easy to promote.

Role of NLRP3 Inflammasome in Heart Failure Patients Undergoing Cardiac Surgery as a Potential Determinant of Postoperative Atrial Fibrillation and Remodeling: Is SGLT2 Cotransporter Inhibition an Alternative for Cardioprotection?

In heart failure (HF) patients undergoing cardiac surgery, an increased activity of mechanisms related to cardiac remodeling may determine a higher risk of postoperative atrial fibrillation (POAF). Given that atrial fibrillation (AF) has a negative impact on the course and management of HF, including the need for anticoagulation therapy, identifying the factors associated with AF occurrence after cardiac surgery is crucial for the prognosis of these patients. POAF is thought to occur when various clinical and biochemical triggers act on susceptible cardiac tissue (first hit), with oxidative stress and inflammation during cardiopulmonary bypass (CPB) surgery being potential contributing factors (second hit). However, the molecular mechanisms involved in these processes remain poorly characterized. Recent research has shown that patients who later develop POAF often have pre-existing abnormalities in calcium handling and activation of NLRP3-inflammasome signaling in their atrial cardiomyocytes. These molecular changes may make cardiomyocytes more susceptible to spontaneous Ca2+-releases and subsequent arrhythmias, particularly when exposed to inflammatory mediators. Additionally, some clinical studies have linked POAF with elevated preoperative inflammatory markers, but there is a need for further research in order to better understand the impact of CPB surgery on local and systemic inflammation. This knowledge would make it possible to determine whether patients susceptible to POAF have pre-existing inflammatory conditions or cellular electrophysiological factors that make them more prone to developing AF and cardiac remodeling. In this context, the NLRP3 inflammasome, expressed in cardiomyocytes and cardiac fibroblasts, has been identified as playing a key role in the development of HF and AF, making patients with pre-existing HF with reduced ejection fraction (HFrEF) the focus of several clinical studies with interventions that act at this level. On the other hand, HFpEF has been linked to metabolic and non-ischemic risk factors, but more research is needed to better characterize the myocardial remodeling events associated with HFpEF. Therefore, since ventricular remodeling may differ between HFrEF and HFpEF, it is necessary to perform studies in both groups of patients due to their pathophysiological variations. Clinical evidence has shown that pharmacological therapies that are effective for HFrEF may not provide the same anti-remodeling benefits in HFpEF patients, particularly compared to traditional adrenergic and renin-angiotensin-aldosterone system inhibitors. On the other hand, there is growing interest in medications with pleiotropic or antioxidant/anti-inflammatory effects, such as sodium-glucose cotransporter 2 inhibitors (SGLT-2is). These drugs may offer anti-remodeling effects in both HFrEF and HFpEF by inhibiting pro-inflammatory, pro-oxidant, and NLRP3 signaling pathways and their mediators. The anti-inflammatory, antioxidant, and anti-remodeling effects of SGLT-2 i have progressively expanded from HFrEF and HFpEF to other forms of cardiac remodeling. However, these advances in research have not yet encompassed POAF despite its associations with inflammation, oxidative stress, and remodeling. Currently, the direct or indirect effects of NLRP3-dependent pathway inhibition on the occurrence of POAF have not been clinically assessed. However, given that NLRP3 pathway inhibition may also indirectly affect other pathways, such as inhibition of NF-kappaB or inhibition of matrix synthesis, which are strongly linked to POAF and cardiac remodeling, it is reasonable to hypothesize that this type of intervention could play a role in preventing these events.

The Association Between Left Ventricular Hypertrophy and the Occurrence and Prognosis of Atrial Fibrillation: A Meta-Analysis

Aims: The aim of this study was to perform a meta-analysis of studies of the association of left ventricular hypertrophy (LVH) and atrial fibrillation (AF), especially the predictive and prognostic role of LVH.

Methods and Results: We searched Medline, Embase, and the Cochrane Library from inception through 10 April 2020. A total of 16 cohorts (133,091 individuals) were included. Compared with the normal subjects, patients with LVH were more susceptible to AF (RR = 1.46, 95% CI, 1.32–1.60). In patients with AF and LVH, there was a higher risk of all-cause mortality during 3.95 years (RR = 1.60, 95% CI, 1.42–1.79), and these patients were more likely to progress to persistent or paroxysmal AF (RR = 1.45, 95% CI, 1.20–1.76) than were patients without LVH. After catheter ablation of AF, patients with LVH were more likely to recur (RR = 1.58, 95% CI, 1.27–1.95).

Conclusion: LVH is strongly associated with AF and has a negative impact on outcome in patients with AF.

Adverse remodeling in atrial fibrillation following isolated aortic valve replacement surgery

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia with adverse clinical outcomes. Aortic valve replacement (AVR) is one of the most frequently performed cardiac surgeries, although there is scarce evidence on arrhythmic outcomes. We aimed to evaluate AF during the first year post- isolated aortic valve replacement surgery and its clinical, analytical, and echocardiographic predictors.

METHODS

Severe aortic stenosis patients with no prior atrial fibrillation submitted to isolated aortic valve replacement surgery were included in our study, of which 316 remained in sinus rhythm and 24 developed AF. We performed logistic regression searching for AF predictors and a longitudinal comparison between pre and post-operative echocardiographic data.

RESULTS

Postoperative AF (POAF), diabetes, and follow-up indexed Left Atrium Diameter (iLAD) were significantly higher in the group of patients developing AF. POAF and iLAD were independent AF predictors at follow-up. No differences between groups were found regarding baseline and follow-up echocardiographic data except for indexed Left Ventricle End-diastolic Diameter (LVED), which failed to decrease after surgery in the AF group.

CONCLUSIONS

POAF and iLAD independently predicted AF at 1 year following isolated AVR surgery in aortic stenosis patients with no AF history. iLVED did not decrease significantly at follow-up in AF patients, possibly reflecting adverse ventricular remodeling.

Suppression of experimental atrial fibrillation in a canine model of rapid atrial pacing by the phosphodiesterase 3 inhibitor cilostazol

OBJECTIVE

Atrial fibrillation (AF) represents the most common arrhythmia encountered in cardiology department. The purpose of this study was designed to investigate whether cilostazol, an oral phosphodiesterase 3 inhibitor (PDE3) could have protective effects on atrial remodeling in a canine model of AF and explore the potential molecular mechanisms.

METHODS

Dogs were randomly assigned to Sham, Paced, Paced + cilostazol group, 7 dogs in each group. In Sham group, pacemaker was instrumented but without pacing. Rapid atrial pacing (RAP) at 600 or 500 bpm/min was maintained in Paced group and Paced + cilo group for 2 h or 2 weeks in acute or chronic experiment, respectively. The Paced + cilo group of dogs were pretreated with cilostazol orally (10 mg·kg^-1·d^-1, cilo) for 1 h or 2 days prior RAP induction and served as treatment group. Atrial effective refractory periods (AERP) at different basic cycle lengths (BCLs), inducibility, and duration time of AF were measured after pacing for 2 h. The blood sample, echocardiography, histopathology, inflammation and oxidative stress makers, protein and mRNA expression levels of matrix metalloproteinase-2 (MMP-2) and MMP-9 were detected after 2 weeks pacing in each group.

RESULTS

Significant changes in electrophysiological parameters were observed in the acute RAP canine model, the AERPs shortened with increased inducibility and duration of AF, which was attenuated by cilostazol (P < 0.05). The serum inflammation makers as interleukin-8 (IL-8) and toll like receptor 4 (TLR 4) levels and oxidative stress indicators like xanthine oxidative (XO) and reactive oxygen species (ROS) in the Paced group was significantly higher than that in Sham group (P < 0.01), and was significantly reduced by cilostazol treatment (P < 0.01). The level of mean platelet volume (MPV) which is one of the platelet indices was significantly elevated in Paced group (P < 0.01). While after cilostazol treated for 2 weeks, the level of MPV was obviously decreased than Paced group (P < 0.01). Pathology and echocardiography studies showed that cilostazol can also prevent RAP induced cardiac fibrosis and structural remodeling. The MPV level has close correlations with IL-8, TLR4, XO and ROS (all P < 0.01). MMP-2 and MMP-9 expression were significantly increased in Paced group (all P < 0.01), which can be attenuated by cilostazol.

CONCLUSIONS

Cilostazol may have protective effects on RAP-induced atrial remodeling by anti-inflammatory, anti-oxidative stress action and regulate the extracellular collagen matrix in a canine model. Moreover, MPV level is associated with inflammation and oxidative stress response of RAP, which might be an important predictors of new-onset and recurrent AF.

Cardiac Biomarkers and Left Ventricular Hypertrophy in Relation to Outcomes in Patients With Atrial Fibrillation: Experiences From the RE - LY Trial

Background

Cardiac biomarkers and left ventricular hypertrophy (LVH) are related to the risk of stroke and death in patients with atrial fibrillation. We investigated the interrelationship between LVH and cardiac biomarkers and their independent associations with outcomes.

Methods and Results

Plasma samples were obtained at baseline in 5275 patients with atrial fibrillation in the RE‐LY (Randomized Evaluation of Long‐Term Anticoagulation Therapy) trial. NT‐proBNP (N‐terminal pro‐B‐type natriuretic peptide), cardiac troponin I and T, and growth differentiation factor‐15 were determined using high‐sensitivity (hs) assays. LVH was defined by ECG. Cox models were adjusted for baseline characteristics, LVH, and biomarkers. LVH was present in 1257 patients. During a median follow‐up of 2.0 years, 165 patients developed a stroke and 370 died. LVH was significantly (P<0.0001) associated with higher levels of all biomarkers in linear regression analyses adjusting for baseline characteristics. Geometric mean ratios (95% CIs) were as follows: NT‐proBNP, 1.32 (1.25–1.38); hs cardiac troponin I, 1.67 (1.57–1.78); hs troponin T, 1.38 (1.32–1.44); and growth differentiation factor‐15, 1.09 (1.05–1.12). For stroke, the hazard ratios (95% CIs) per 50% increase were as follows: NT‐proBNP, 1.09 (1.00–1.19); hs cardiac troponin I, 1.09 (1.03–1.15); hs troponin T, 1.14 (1.06–1.24); and growth differentiation factor‐15, 1.22 (1.08–1.38) (all P<0.05). For death, hazard ratios (95% CIs) were as follows: NT‐proBNP, 1.24 (1.17–1.31); hs cardiac troponin I, 1.13 (1.10–1.17); hs troponin T, 1.28 (1.23–1.34); and growth differentiation factor‐15, 1.31 (1.22–1.42) (all P<0.0001). LVH was not significantly associated with stroke or death after adjustment for biomarkers.

Conclusions

Cardiac biomarkers are significantly associated with LVH. The prognostic value of biomarkers for stroke and death is not affected by LVH. The prognostic information of LVH is attenuated in the presence of cardiac biomarkers.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00262600.

Electrocardiographic left ventricular hypertrophy predicts recurrence of atrial arrhythmias after catheter ablation of paroxysmal atrial fibrillation

BACKGROUND

Left ventricular hypertrophy (LVH) is an independent predictor of new-onset atrial fibrillation. Whether LVH can predict the recurrence of arrhythmia after radiofrequency catheter ablation (RFCA) in patients with paroxysmal atrial fibrillation (PAF) remains unclear.

HYPOTHESIS

PAF patients with baseline-electrocardiographic LVH has a higher recurrence rate after RFCA procedure compared with those without LVH.

METHODS

A total of 436 patients with PAF undergoing first RFCA were consecutively enrolled and clustered into 2 groups based on electrocardiogram (ECG) findings: non-ECG LVH (218 patients) and ECG LVH (218 patients). LVH was characterized by the Romhilt-Estes point score system; the score ≥5points were defined as LVH.

RESULTS

At 42 months' (interquartile range, 18.0-60.0 months) follow-up after RFCA, 151 (69.3%) patients in the non-ECG LVH group and 108 (49.5%) patients in the ECG LVH group maintained sinus rhythm without using antiarrhythmic drugs (P < 0.001). Patients with ECG LVH tended to experience a much higher prevalence of stroke and recurrence of atrial arrhythmia episodes compared with those without ECG LVH (log-rank P < 0.001). Multivariate analysis found the presence of ECG LVH and left atrial diameter to be independent risk factors for recurrence after adjusting for confounding factors.

CONCLUSIONS

The presence of ECG LVH was a strong and independent predictor of recurrence in patients with PAF following RFCA.

Is 10-second electrocardiogram recording enough for accurately estimating heart rate in atrial fibrillation

BACKGROUND

At present, the estimation of rest heart rate (HR) in atrial fibrillation (AF) is obtained by apical auscultation for 1min or on the surface electrocardiogram (ECG) by multiplying the number of RR intervals on the 10second recording by six. But the reasonability of 10second ECG recording is controversial.

METHODS

ECG was continuously recorded at rest for 60s to calculate the real rest HR (HR60s). Meanwhile, the first 10s and 30s ECG recordings were used for calculating HR10s (sixfold) and HR30s (twofold). The differences of HR10s or HR30s with the HR60s were compared. The patients were divided into three sub-groups on the HR60s <80, 80-100 and >100bpm.

RESULTS

No significant difference among the mean HR10s, HR30s and HR60s was found. A positive correlation existed between HR10s and HR60s or HR30s and HR60s. Bland-Altman plot showed that the 95% reference limits were high as -11.0 to 16.0bpm for HR10s, but for HR30s these values were only -4.5 to 5.2bpm. Among the three subgroups with HR60s <80, 80-100 and >100bpm, the 95% reference limits with HR60s were -8.9 to 10.6, -10.5 to 14.0 and -11.3 to 21.7bpm for HR10s, but these values were -3.9 to 4.3, -4.1 to 4.6 and -5.3 to 6.7bpm for HR30s.

CONCLUSION

As 10s ECG recording could not provide clinically accepted estimation HR, ECG should be recorded at least for 30s in the patients with AF. It is better to record ECG for 60s when the HR is rapid.

Inappropriate left ventricular mass and poor outcomes in patients with angina pectoris and normal ejection fraction

OBJECTIVES

Although inappropriate left ventricular mass has been associated with clustered cardiac geometric and functional abnormalities, its predictive value in patients with coronary artery disease is still unknown. This study examined the association of inappropriate left ventricular mass with clinical outcomes in patients with angina pectoris and normal ejection fraction.

PARTICIPANTS AND METHODS

Consecutive patients diagnosed with angina pectoris whose ejection fraction was normal were recruited from 2008 to 2012. Inappropriate left ventricular mass was determined when the ratio of actual left ventricular mass to the predicted one exceeded 150%. The primary endpoint was a composite of all-cause death, nonfatal myocardial infarction, and nonfatal stroke. Clinical outcomes between the inappropriate and appropriate left ventricular mass group were compared before and after propensity matching.

RESULTS

Of the total of 1515 participants, 18.3% had inappropriate left ventricular mass. Patients with inappropriate left ventricular mass had a higher composite event rate compared with those with appropriate left ventricular mass (11.2 vs. 6.6%, P=0.010). Multivariate Cox regression analyses showed that inappropriate left ventricular mass was an independent risk factor for adverse events (adjusted hazard ratio, 1.59; 95% confidence interval, 1.03-2.45; P=0.035). The worse outcome in patients with inappropriate left ventricular mass was further validated in a propensity matching cohort and patients with the traditional definition of left ventricular hypertrophy.

CONCLUSION

Inappropriate left ventricular mass was associated with an increased risk of adverse events in patients with angina pectoris and normal ejection fraction.

Anemia as an Independent Predictor of Adverse Cardiac Outcomes in Patients with Atrial Fibrillation

BACKGROUND

Anemia and echocardiographic systolic and diastolic parameters are useful predictors of cardiovascular outcomes in patients with atrial fibrillation (AF). However, no studies have evaluated the use of anemia for predicting cardiovascular outcome in AF patients when the important echocardiographic parameters are known. Therefore, this study was designed to evaluate whether low hemoglobin is a useful parameter for predicting poor cardiac outcome after adjustment for important echocardiographic parameters in AF patients.

METHODS

Index beat method was used to measure echocardiographic parameters in 166 patients with persistent AF. Cardiac events were defined as death and hospitalization for heart failure. The association of hemoglobin with adverse cardiac events was assessed by Cox proportional hazards model.

RESULTS

The 49 cardiac events identified in this population included 21 deaths and 28 hospitalizations for heart failure during an average follow-up of 20 months (25th-75th percentile: 14-32 months). Multivariable analysis showed that increased left ventricular mass index (LVMI) and decreased body mass index, estimated glomerular filtration rate, and hemoglobin (hazard ratio 0.827; P = 0.015) were independently associated with increased cardiac events. Additionally, tests of a Cox model that included important clinic variables, LVMI, left ventricular ejection fraction, and the ratio of transmitral E-wave velocity to early diastolic mitral annulus velocity showed that including hemoglobin significantly increased value in predicting adverse cardiac events (P = 0.010).

CONCLUSIONS

Hemoglobin is a useful parameter for predicting adverse cardiac events, and including hemoglobin may improve the prognostic prediction of conventional clinical and echocardiographic parameters in patients with AF.