Impact of ratio of P-wave duration to P-wave amplitude on recurrent arrhythmia characteristics and low-voltage risk score in paroxysmal atrial fibrillation patients underwent catheter ablation

The Role of P-Wave Variables in Enhancing Prediction of New-Onset Atrial Fibrillation in Patients With Acute Myocardial Infarction

BACKGROUND

After acute myocardial infarction (AMI), it is common to observe new-onset atrial fibrillation (NOAF), which is often related to a negative prognosis. Some P-wave variables (P-wave duration [PWD], P-wave amplitude, and interatrial block [IAB]), reflecting the process of electrical and structural remodeling, could predict the risk of atrial fibrillation (AF). This study aimed to assess the predictive value of P-wave variables for post-AMI NOAF.

METHODS

We retrospectively analyzed 1581 AMI patients with no prior AF, using follow-up data from January 2023 to January 2024. P-wave variables were measured, and patients were grouped based on in-hospital NOAF occurrence.

RESULTS

Overall, 164 (10.3%) of the 1581 patients had NOAF. The age (61.08 ± 12.02 vs. 67.91 ± 11.60, p < 0.001), left atrial size (36.31 ± 3.94 vs. 39.12 ± 5.51, p < 0.001), Brain Natriuretic Peptide (1588.45 ± 3346.18 vs. 3864.39 ± 6251.92, p < 0.001), P-wave variables (PWD: 102.78 ± 12.56 vs. 117.88 ± 18.81, p < 0.001; P-wave amplitude: 0.12 ± 0.04 vs. 0.13 ± 0.04, p = 0.041; interatrial block: 89.6% vs. 10.3%, p < 0.001), congestive heart failure (4.7% vs. 23.2%, p < 0.001), and Killip > 1 (25.3% vs. 55.5%, p < 0.001) showed significant differences between the non-AF and NOAF groups. P-wave variables were significantly associated with an increased risk of NOAF in multivariable regression analysis.

CONCLUSIONS

The addition of P-wave variables to AF risk factors from literature and guidelines significantly improved NOAF risk discrimination. P-wave variables were strongly associated with NOAF after AMI. Adding these variables enhanced the predictive performance for post-AMI NOAF.

Impact of combining ablation index-guided and very high-power short-duration ablation at posterior wall adjacent to esophagus during perioperative period on procedural factors

INTRODUCTION

The impact of combining ablation index (AI)-guided and very high-power short-duration (vHPSD) ablation on procedural factors at the posterior wall near the esophagus is unclear.

METHODS

Atrial fibrillation patients who underwent initial ablation using three-dimensional mapping were enrolled. Patients were classified into two groups: those who underwent only AI-guided pulmonary vein isolation (PVI) (AI group) and those who underwent vHPSD ablation at the posterior wall adjacent to the esophagus in addition to AI-guided PVI (AI + vHPSD group). Differences in myocardial injury, inflammation, procedural characteristics, and pulmonary vein (PV) reconnection patterns were assessed between the two groups.

RESULTS

This study included 167 patients (AI group, 83 patients; AI+vHPSD group, 84 patients). No significant differences in high-sensitive troponin I or changes in inflammatory markers between pre- and Postablation were observed in either group. Total application time and total application energy were significantly lower in the AI+vHPSD group than in the AI group (p < 0.001 for both) despite no significant difference in the total number of applications between the groups. The incidence of esophagus temperature ≥40 degrees was significantly lower in the AI+vHPSD group than in the AI group (p = 0.036). However, the incidence of PV reconnections near the esophagus was significantly higher in the AI+vHPSD group than in the AI group (11.9% vs 3.6%, p = 0.046), despite no significant difference in the incidence of PV reconnections overall.

CONCLUSION

The combination of AI-guided PVI and vHPSD adjacent to the esophagus demonstrated reduced application energy requirements and maintained safety and effectiveness during the perioperative period.

Prognostic significance of ratio of P-wave duration to P-wave vector magnitude for mortality in acute anterior myocardial infarction

BACKGROUND

The impact of P-wave abnormality in acute anterior MI, where the culprit vessel is the left anterior descending artery, remains undetermined. This study aimed to elucidate the impact of P-wave morphology on clinical outcomes in acute anterior MI.

METHODS

Patients undergoing emergent percutaneous coronary intervention for acute anterior MI were enrolled between September 2014 and April 2019 (derivation cohort) and May 2019 through July 2023 (validation cohort). P-wave duration (Pd) and P-wave vector magnitude (Pvm) were measured. The Pvm was calculated as the square root of the sum of the squared P-wave magnitudes in leads II and V6 and one-half of the P-wave amplitude in V2. The patients were categorized into high and low Pd/Pvm groups using a statistically derived cut-off value. The endpoint comprised the composite of heart failure (HF) hospitalization and all-cause death.

RESULTS

Consecutive 426 patients were enrolled in this study (derivation cohort, 213 patients; validation cohort, 216 patients). The calculated cut-off value of Pd/Pvm for predicting the clinical endpoint, determined through receiver operating curve analysis, was 793.5 ms/mV (area under the curve [AUC] = 0.85, sensitivity of 73.8 %, and specificity of 94.0 %) in the derivation cohort. Kaplan-Meier analyses revealed a significantly higher risk of the endpoint in patients with high Pd/Pvm than those with low Pd/Pvm in derivation and validation cohorts (Log-rank p < 0.001 and p < 0.001, respectively). Multivariate Cox proportional hazards analysis identified advanced age, elevated Pd/Pvm, and reduced left ventricular ejection fraction as independent and significant factors associated with the endpoint in the validation cohort (p = 0.008, p < 0.001, and p < 0.001, respectively).

CONCLUSION

High Pd/Pvm was significantly associated with the composite of HF hospitalization and all-cause death after acute anterior MI.

ST-segment depression and left ventricular systolic function recovery post-atrial fibrillation ablation in heart failure

AIMS

Catheter ablation (CA) of atrial fibrillation (AF) improves left ventricular ejection fraction (LVEF) in patients with heart failure with reduced ejection fraction (HFrEF). The impact of ST-segment depression before CA on LVEF recovery and clinical outcomes remains unknown. In the present study, we aimed to investigate the relationship between ST-segment depression during AF rhythm before CA and improvement in the LVEF and clinical outcomes in persistent atrial fibrillation (PerAF) patients with HFrEF.

METHODS AND RESULTS

The present study included 122 PerAF patients (male; 98 patients, 80%, mean age: 69 [56, 76] years) from the Osaka Rosai Atrial Fibrillation ablation (ORAF) registry who had LVEF < 50% and underwent an initial ablation. The patients who underwent percutaneous coronary intervention or coronary artery bypass grafting within the past 1 month were not included in the enrolled patients. We assigned the patients based on the presence of ST-segment depression before CA during AF rhythm and evaluated improvement in the LVEF (LVEF ≥ 15%) 1 year after CA and the relationship between ST-segment depression and heart failure (HF) hospitalization/major adverse cardiovascular events (MACE), which are defined as a composite of HF hospitalization, cardiovascular death, hospitalization due to coronary artery disease, ventricular arrhythmia requiring hospitalization and stroke. The percentage of patients with improvement in the LVEF 1 year after CA was significantly lower in the patients with ST-segment depression than those without (58.6% vs. 79.7%, P = 0.012). Multiple regression analysis showed ST-segment depression was independently and significantly associated with improvement in the LVEF 1 year after CA (HR: 0.35; 95% CI: 0.129-0.928, P = 0.035). Kaplan-Meier analysis showed that the patients with ST-segment depression significantly had higher risk of HF hospitalization and MACE than those without (log rank P = 0.022 and log rank P = 0.002, respectively). Multivariable Cox proportional hazards analysis showed that ST-segment depression was independently and significantly associated with a higher risk of MACE (HR: 2.82; 95% CI: 1.210-6.584, P = 0.016).

CONCLUSIONS

ST-segment depression before CA during AF rhythm was useful prognostic predictor of improvement in the LVEF and clinical outcomes including HF hospitalization and MACE in PerAF patients with HFrEF.

Comparison of Postprocedural P-Wave Vector Magnitude on 12-Lead Electrocardiogram Between Cryoballoon and Radiofrequency Ablation

Pulmonary vein isolation (PVI) causes changes in P-wave parameters. However, the difference in changes in P-wave parameters including P-wave vector magnitude (Pvm) between radiofrequency catheter ablation (RFCA) and cryoballoon ablation (CBA) remains unknown. Paroxysmal atrial fibrillation (PAF) patients who underwent only PVI were enrolled. Pvm was calculated by the square root of the sum of the squared P-wave amplitude in leads II and V6 and one-half of the P-wave amplitude in V2. The patients were divided into 2 groups: RFCA and CBA. ΔPvm was calculated as ΔPvm (mV) = (Pvm at pre-PVI)-(Pvm at post-PVI). The following factors were evaluated: (1) differences in the ΔPvm between the 2 groups, (2) relation between late arrhythmia recurrence and ΔPvm in RFCA and CBA groups, and (3) the impact of relevant factors on ΔPvm. The study population included a total of 426 patients with PAF (RFCA, 167 patients; CBA, 259 patients). ΔPvm was significantly larger in CBA than in RFCA (p <0.001). Kaplan-Meier analysis showed late arrhythmia recurrence was significantly higher in patients with low ΔPvm (<0.019 mV) than high ΔPvm (≥0.019 mV) in RFCA (Log-rank p <0.001), and low ΔPvm (<0.033 mV) than high ΔPvm (≥0.033 mV) in CBA (Log-rank p <0.001). Multiple regression analysis showed that CBA and heart rate change were independently and significantly associated with ΔPvm (p <0.001 and p <0.001, respectively). In conclusion, ΔPvm was significantly larger in CBA than RFCA during procedure. Low ΔPvm had a higher risk of late arrhythmia recurrence in RFCA and CBA.