(Reuters) -Johnson & Johnson said on Wednesday it had temporarily paused the rollout of its Varipulse heart device in the United States, as the company investigates four reported stroke events. The Manufacturer and User Facility Device Experience (MAUDE),

Johnson & Johnson MedTech has temporarily paused all U.S. external evaluations and cases using its Varipulse pulse field ablation (PFA) system

In that single-arm study, the rate of primary adverse events within 7 days of ablation was 2.9%, with the most common complication being pericardial tamponade (1.1%), and a few cases of stroke (0.7%) and transient ischemic attack (0.4%).

Despite the pause, the company clarified that the suspension does not impact commercial activity outside the US.

“On January 5, out of an abundance of caution, Johnson & Johnson MedTech temporarily paused the U.S. External Evaluation and all U.S. Varipulse cases while we investigate the root cause of four reported neurovascular events in the U.S. External Evaluation,” the company said in its notice.

Johnson & Johnson shares are down 3% Wednesday on safety concerns that could dim sales prospects for a new heart device, while its rivals gained. J&J said it temporarily paused the use of the heart device,

Johnson & Johnson said on Wednesday it temporarily paused the rollout of its Varipulse heart device in the United States as the company investigates four reported stroke events.