Stroke after Aortic Valve Replacement: The Known and Unknown
Stroke following aortic valve surgery is known as a devastating complication and is associated with increased morbidity and mortality.1 Transcatheter aortic valve replacement (TAVR) has emerged as a valid alternative for surgical aortic valve replacement (SAVR) in both inoperable patients and in those at high risk for surgery; however, the encouraging results were hampered by various complications including stroke. In the pivotal Placement of AoRTic TraNscathetER (PARTNER) trial, the initial stroke rates of TAVR patients were almost double in comparison to patients who underwent SAVR (3.8% vs. 2.1%; p=0.2);2 and this potentially impacted the decision to choose one procedure over the other. However, continued follow-up up to 3 years equated the stroke rates in SAVR and TAVR. More recent surgical and TAVR data indicate that stroke rates in both procedural alternatives had declined, with rates of 1.7-2.5% from large registries, such as the Society for Thoracic Surgeons (STS) and the German Aortic Valve registries.3,4 However, the unknowns with respect to stroke following AVR are numerous. When evaluating neurological complications, overt clinical and obvious disabling stroke is only one potential neurological event that could occur after the procedure, and as opposed to permanent neurological deficit, these events are either clinically silent or go unnoticed due to the fact that physicians are not performing tests to rule out these events (i.e., cognitive deficits). The incidence and impact of these events on outcome is unknown. Further, the role and impact of magnetic resonance imaging (MRI) detection of silent strokes also remains unknown.
- Received March 19, 2014.
- Accepted March 21, 2014.