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Week-long continuous ECG monitoring was a worthwhile addition to the workup before transcatheter aortic valve replacement (TAVR), a small study suggested.

Monitoring with the wearable CardioSTAT device over 7 days revealed arrhythmic events in 51 of 106 TAVR candidates, changing the treatment plan for 14 of them (such as starting anticoagulation) in the 3 months preceding TAVR, according to Josep Rodés-Cabau, MD, of Quebec Heart and Lung Institute at Laval University, Quebec City, and colleagues.

Each person averaged two arrhythmic episodes, according to the paper published online in.

"The interesting findings of this study raise some questions, namely are new-onset arrhythmias really new-onset arrhythmias? And should we routinely perform a 7-day ECG before TAVR?" said Stefan Toggweiler, MD, and Richard Kobza, MD, both of Heart Center Lucerne in Switzerland, in an .

"Addition of a 7-day ECG will further increase the complexity of pre-procedural planning," which already includes a gated CT scan, coronary angiography, blood work, and a 12-lead ECG, according to the editorialists.

In the study, newly diagnosed tachyarrhythmic events were found in 37 of the 106 patients (nearly all asymptomatic). Atrial fibrillation (Afib) or tachycardia was detected in eight patients that were not known to harbor such irregularities, and nonsustained ventricular arrhythmias were detected in 31.

"Although the number of patients was low in this study, this intriguing finding suggests that many, if not the majority, of patients with so-called new-onset Afib may actually have pre-existing, but undetected, Afib," Toggweiler and Kobza noted.

Significant bradyarrhythmias were seen in 22 patients (all but two asymptomatic). Of this group, eight underwent a treatment change and four a permanent pacemaker insertion. Bradyarrhythmias were especially common in people with pre-existing first-degree atrioventricular block (six of 20 patients) and right bundle branch block (RBBB; seven of 15).

In general, the predictors of arrhythmic events pre-TAVR were chronic renal failure, higher valve calcification, and left ventricular dysfunction.

"These findings support the usefulness of CEM [continuous ECG monitoring] for the early diagnosis and treatment of arrhythmic events in TAVR candidates. Also, they open the door to further studies evaluating the possibility of tailored CEM pre-TAVR in selected populations with certain baseline clinical features," according to Rodés-Cabau's group.

It may be that "RBBB is not only a risk factor for a , but appears to indicate a generally more vulnerable conduction system with an increased incidence of bradyarrhythmias before TAVR," Toggweiler and Kobza said. "The study suggests that at least a subset of patients with a pre-existing RBBB may have a good indication for a PPM already before undergoing TAVR."

Investigators performed their prospective single-center study on TAVR candidates with severe aortic stenosis and no prior permanent pacemaker.

Eligible patients had to have adequate ECG data, collected with the single-use, wire-free CardioSTAT patch device, which performs continuous ECG recording of a single-lead tracing for up to 14 days. Devices were returned in person or by mail for analysis by the investigators before TAVR.

After TAVR, patients were monitored by telemetry until hospital discharge. New-onset arrhythmic events occurred in 20 of the 90 patients eventually undergoing TAVR. Continuous ECG monitoring pre-TAVR had allowed early arrhythmia diagnosis in one-third of them.

Rodés-Cabau and colleagues acknowledged the relatively small sample in the study and its limited generalizability to other centers. Additionally, they noted that a quarter of patients had previously documented Afib and that the single-lead design of CardioSTAT did not allow them to assess the incidence of new-onset left bundle branch block (LBBB) before TAVR.

"A prospective randomized controlled study would strengthen these indications and achieve a broader acceptance of 7-day ECG monitoring," commented Toggweiler and Kobza.

Nevertheless, on the basis of the present study alone, they wrote, "it appears reasonable to perform a 7-day ECG in TAVR patients with preexisting conduction disorders and borderline indication for a PPM. Also, such a test may be considered in patients with severe chronic kidney disease, heavily calcified valves, or reduced left ventricular function."

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