Premature atrial complexes in an ischemic stroke population and risk of recurrent stroke: a systematic review

Burden of Premature Atrial Complexes and Risk of Recurrent Stroke and Death in Patients with Mild to Moderate Ischemic Stroke

BACKGROUND

Premature atrial complexes (PACs) meet increased attention as a potential intermediary between sinus rhythm and atrial fibrillation (AF). Patients with even high numbers of PACs do not fulfill current guidelines for oral anticoagulation treatment though an associated stroke risk is suspected.

OBJECTIVE

We aimed to determine whether a high number of PACs or runs of AF less than 30 seconds in 2-day continuous electrocardiogram (ECG) recording was associated with risk of recurrent ischemic stroke/transient ischemic attack (TIA) or death in a large cohort of patients with acute ischemic stroke or TIA and no prior AF.

METHODS

We performed 48 hours continuous ECG recording within 1 week after ischemic stroke/TIA. PACs were reported as mean number of PACs per hour. Patients were followed in Danish Stroke Registry, Danish Civil Registration System, and Danish National Patient Registry. Cox Regression analysis was used to calculate hazard ratios.

RESULTS

We included 1507 patients with TIA (40%) or ischemic stroke (60%), of which 98.7% had mild to moderate strokes. Mean age was 72.9 (7.8) years, 43.4% were females. Follow-up was 2.3 (1.3) years. Hazard ratio for recurrent stroke/TIA or death did not differ between quartiles of PAC burden, nor did any of the 2 components of this composite endpoint. Nonsustained AF less than 30 seconds was not associated with higher risk of recurrent stroke/TIA or death.

CONCLUSIONS

In a large cohort of patients with recent ischemic stroke or TIA, burden of PACs or nonsustained AF less than 30 seconds were not associated to higher risk of recurrent stroke/TIA or death.

Association between excessive premature atrial complexes and cryptogenic stroke: results of a case-control study

OBJECTIVE

Recent anticoagulation trials in all-comer cryptogenic stroke patients have yielded equivocal results, reinvigorating the focus on identifying reproducible markers of an atrial myopathy. We investigated the role of excessive premature atrial complexes (PACs) in ischaemic stroke, including cryptogenic stroke and its association with vascular risk factors.

METHODS AND RESULTS

A case-control study was conducted utilising a multicentre institutional stroke database to compare 461 patients with an ischaemic stroke or transient ischaemic attack (TIA) with a control group consisting of age matched patients without prior history of ischaemic stroke/TIA. All patients underwent 24-hour Holter monitoring during the study period and atrial fibrillation was excluded. An excessive PAC burden, defined as ≥200 PACs/24 hours, was present in 25.6% and 14.7% (p<0.01), of stroke/TIA and control patients, respectively. On multivariate regression, excessive PACs (OR 1.97; 95% CI 1.29 to 3.02; p<0.01), smoking (OR 1.58; 95% CI 1.06 to 2.36; p<0.05) and hypertension (OR 1.53; 95% CI 1.07 to 2.17; p<0.05) were independently associated with ischaemic stroke/TIA. Excessive PACs remained the strongest independent risk factor for the cryptogenic stroke subtype (OR 1.95; 95% CI 1.16 to 3.28; p<0.05). Vascular risk factors that promote atrial remodelling, increasing age (≥75 years, OR 3.64; 95% CI 2.08 to 6.36; p<0.01) and hypertension (OR 1.54; 95% CI 1.01 to 2.34; p<0.05) were independently associated with excessive PACs.

CONCLUSIONS

Excessive PACs are independently associated with cryptogenic stroke and may be a reproducible marker of atrial myopathy. Prospective studies assessing their utility in guiding stroke prevention strategies may be warranted.