A Simple Electrocardiography to Predict Mortality in TAVR

Conduction abnormalities, such as new left bundle branch block, atrioventricular block, and need for a pacemaker, are still among the most frequent complications in transcatheter aortic valve replacement (TAVR). New valve generations have (mostly) not managed to reduce significantly electrical abnormalities; furthermore, some modifications such as external skirts, which are extremely effective for the reduction of aortic failure, have caused a rise in the rates of pacemaker implantation.

Complete right bundle branch block before the procedure is clearly associated with the need for a new pacemaker, but whether this would translate into future clinical events was still unclear.

This study sought to find out whether baseline right bundle branch block is associated with clinical events in patients who undergo TAVR, both with balloon-expandable and self-expandable valves.

Read Also: “Lotus Valve performance related to pacemaker implantation in patients after TAVR”.

A total of 3527 patients undergoing TAVR were evaluated according to the presence or absence of complete right bundle branch block on baseline electrocardiography, which was observed in 362 of all patients (10.3%).

This abnormality in the baseline electrocardiography tripled the need for pacemaker after the procedure (40.1% vs. 13.5%; p < 0.001), an association that was well-known and expected, but it was also associated with a significant increase in mortality (10.2% vs. 6.9%; p = 0.024).

In a mean follow-up at 20 ± 18 months, complete bundle branch block was associated with all-cause death (hazard ratio [HR]: 1.31; 95% confidence interval [CI]: 1.06 to 1.63; p = 0.014) and cardiovascular death (HR: 1.45; 95% CI: 1.11 to 1.89; p = 0.006), but not with sudden death.

Read Also: “Post TAVR Dialysis: a Severe Complication Less and Less Frequent”.

Conclusion

Right bundle branch block can be observed in 10% of all patients who undergo transcatheter aortic valve replacement and is associated with poorer clinical outcomes. Patients without permanent pacemaker at hospital discharge from the procedure present a high risk for high-degree atrioventricular block and sudden death.

Editorial

Up to 60% of all patients present acute left bundle branch block, an abnormality that persists at discharge in about half the cases. If this happens in a patient with prior right bundle branch block, the result is an acute complete block that does not endanger the patient due to immediate pacemaker implantation.

The problem is that a minority (about 1% of all patients) may present left bundle branch block within 3 months, once the patient has been discharged and is at home. This phenomenon could explain the rise in cardiovascular mortality fundamentally among patients who were discharged from the procedure without having received a pacemaker.

Original title: Clinical Impact of Baseline Right Bundle Branch Block in Patients Undergoing Transcatheter Aortic Valve Replacement.

Reference: Vincent Auffret et al. J Am Coll Cardiol Intv 2017. Article in press.

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