Incremental Changes in QRS Duration Predict Mortality in Patients with Atrial Fibrillation

Clinical implications and risk factors for QRS prolongation over time in heart failure patients

BACKGROUND

QRS prolongation is an established prognostic marker in heart failure (HF). In contrast, the role of QRS width progression over time has been incompletely explored. The current study investigates the role of QRS width progression over time on clinical status and identifies underlying predictors.

METHODS

Datasets of ≥ 2 consecutive visits from 100 attendees to our HF clinic between April and August 2021 were analysed for changes in QRS complex duration.

RESULTS

In total 240 datasets were stratified into tertiles based on change in QRS duration (mm/month) (1st tertile: - 1.65 [1.50] 'regression'; 2nd tertile 0.03 [0.19] 'stable', 3rd tertile 3.57 [10.11] 'progression'). The incidence of the combined endpoint HF hospitalisation and worsening of symptomatic heart failure was significantly higher in the group with QRS width progression (3rd tertile) compared with the stable group (2nd tertile; log-rank test: p = 0.013). These patients were characterised by higher plasma NT-pro-BNP levels (p = 0.008) and higher heart rate (p = 0.007). A spline-based prediction model identified patients at risk of QRS width progression when NT-pro-BNP and heartrate were > 837 pg/ml and > 83/bpm, respectively. These markers were independent of guideline-directed medical HF therapy. Patients beyond both thresholds had a 14-fold increased risk of QRS width progression compared to those with neither or either alone (HR: 14.2 [95% 6.9 - 53.6]; p < 0.0001, p for interaction = 0.016).

CONCLUSIONS

This pilot study demonstrates that QRS width progression is associated with clinical deterioration of HF. NTproBNP plasma levels and heart rate indicate patients at risk QRS width progression, independently of HF therapy.

Relation of Increasing QRS Duration Over Time and Cardiovascular Events in Outpatients With Heart Failure

An increase in the duration of the QRS complex over time has been shown to be associated with poor clinical outcomes in specific subgroups of heart failure (HF) patients. There is a paucity of data on the clinical impact of increasing QRS duration on outcomes in HF with narrow QRS duration. This was a retrospective study of consecutive adult referrals to a tertiary outpatient HF clinic over a 2-year period. All patients with a narrow QRS, (<130 ms) were included. The primary outcome was mortality. Secondary outcomes were HF hospitalization and a composite of HF hospitalization, implantation of cardiac resynchronization therapy or left ventricular assist device and cardiac transplant. A total of 253 patients with 2 or more QRS measurments were included. Death occurred in 41 patients (16%), 258 HF hospitalizations occurred in 116 patients (46%) and the composite occurred in 127 patients (50%). Multivariable analyses found that a rate of QRS duration change of ≥1 ms/month was independently associated with increased mortality (odds ratio [OR] 2.26, 95% confidence interval [CI] 1.04 to 4.91), HF hospitalization (relative risk [RR] 2.01, 95% CI 1.37 to 2.94), and the composite (OR 2.40, 95%CI 1.44 to 4.02). A new QRS >130 ms was also independently associated with mortality (OR 3.27, 95%CI 1.29-8.32), HF hospitalization (RR 2.75, 95% CI 1.72 to 4.4) and the composite (OR 2.52, 95%CI 1.27 to 4.99). In conclusion, in patients with HF and a narrow baseline QRS, an increase in QRS duration of ≥1 ms per month is associated with increased mortality and HF hospitalization. HF patients may benefit from serial monitoring of QRS duration.

Association between paced QRS duration and atrial fibrillation after permanent pacemaker implantation: A retrospective observational cohort study

Right ventricular pacing often results in prolonged QRS duration (QRSd) as the result of right ventricular stimulation, and atrial fibrillation (AF) may result. The association of pacing-induced prolonged QRSd and AF in patients with permanent pacemakers is unknown.We selected 180 consecutive patients who underwent pacemaker implantation for complete/advanced atrioventricular block. All of the patients were paced from the right ventricular septum. Electrocardiography recordings were obtained at the beginning and the end of pacemaker implantation. QRSd was measured in all 12 leads. The QRSd variation was calculated by subtracting the preimplantation QRSd from the postimplantation QRSd.The occurrence of AF was observed in 64 (35.56%) patients (follow-up 33.62 ± 21.47 mo). No significant differences in preimplantation QRSd were observed between the AF occurrence and nonoccurrence groups. The QRSd variation in leads V4 (54.22 ± 29.03 vs 42.66 ± 33.79 ms, P = .022), and V6 (64.62 ± 23.16 vs 48.45 ± 34.40 ms, P = .001) differed significantly between the occurrence and nonoccurrence groups. More QRSd variation in lead V6 (P = .005, HR = 1.822, 95% CI 1.174-2.718, interval scale of QRSd was 40 ms) and left atrial diameter (P = .045, HR = 1.042, 95% CI 1.001-1.086) were independent risk factors for AF occurrence. Receiver operating characteristic curve suggested that QRSd variation in lead V6 could predict AF occurrence, especially for patients with long preimplantation QRSd (≥120 ms, area under the curve was 0.826, 95% CI 0.685-0.967).QRSd variation in lead V6 might be positively correlated with postimplantation AF occurrence. In patients with pacemaker implantation, QRSd could be a complementary criterion for optimizing the right ventricular septal pacing site, and smallest QRSd might be worth pursuing.

Frailty severity is significantly associated with electrocardiographic QRS duration in chronic dialysis patients

End-stage renal disease (ESRD) patients are at increased risk of sudden cardiac death, the risk of which is presumably related to arrhythmia. Electrocardiographic (ECG) parameters have been found to correlate with arrhythmia and predict cardiovascular outcomes in ESRD patients. Frailty is also a common feature in this population. We investigate whether the severity of dialysis frailty is associated with ECG findings, including PR interval, QRS duration, and QTc interval. Presence and severity of frailty was ascertained using six different self-report questionnaires with proven construct validity. Correlation analysis between frailty severity and ECG was made, and those with significant association entered into multiple regression analysis for confirmation. Among a cohort of chronic hemodialysis patients, we found that frailty severity, assessed by the Edmonton frailty scale, is significantly associated with QRS duration (r = − 0.3, p < 0.05). Dialysis patients with QRS longer than 120 ms had significantly lower severity of frailty than those with QRS less than 120 ms (p = 0.01 for the Edmonton frailty scale and 0.05 for simple FRAIL scale). Regression analysis showed that frailty severity, assessed by the Edmonton frailty scale and simple FRAIL scale, was significantly associated with QRS duration independent of serum electrolyte levels. In conclusion, a significant relationship exists between the severity of frailty and QRS duration in ESRD patients. This might be an under-recognized link between frailty and its adverse cardiovascular impact in these patients.