Key result
Coexisting prosthetic valves and AF are linked to ~9-fold more cerebral microemboli vs NVAF.
Why the study?
Does Transcranial Doppler monitoring detect differences in cerebral microemboli frequency among patients with atrial fibrillation, prosthetic valves, and previous stroke?
Observational (n=86)
Does Transcranial Doppler monitoring detect differences in cerebral microemboli frequency among patients with atrial fibrillation, prosthetic valves, and previous stroke?
Absolute Event Rate: 12.3% vs 1.4%
p-value: p=0.007
Transcranial Doppler monitoring can detect cerebral microemboli, the frequency of which correlates with the severity of cardiac embolic risk factors and a history of previous stroke.
May signal higher embolic risk in prosthetic valve-AF overlap; leaves open whether TCD monitoring should guide therapy.
Transcranial Doppler (TCD) monitoring of the middle cerebral artery (MCA) permits the detection of high intensity transient signals (HITS), which are believed to represent microemboli. Non-valvular atrial fibrillation (NVAF) and prosthetic heart valves (PV) are important risk factors for embolic stroke. We evaluated both the prevalence and the frequency of microemboli in these high risk groups and the correlation with previous stroke. Sixty-six patients were monitored for 30 min on both MCAs sequentially. Twenty healthy subjects were studied as well. The total number of HITS recorded on both sides, expressed as HITS/h, was used for comparison. In NVAF patients (n = 24) the prevalence of HITS was 25%, in PV (n = 16) 62% and in those patients in whom PV coexisted with atrial fibrillation (PVAF) (n = 26), it was 42%. None in the control group showed HITS. HITS occurred significantly more frequently in PVAF (12.3/h) than in both NVAF (1.4/h, p = 0.007) and PV (2.7/h, p = 0.011), whereas there was no difference between PV and NVAF. The prevalence of HITS was not statistically different in patients with and without previous stroke, but among HITS positive patients those with previous stroke had a significantly higher HITS frequency (18.9 vs 8.5/h, p = 0.04). In conclusion, in patients with cardiac embolic sources the frequency of HITS increases from the classes with the lower (NVAF, PV) to the class with the highest (PVAF) risk factor. Patients with previous stroke have more HITS than asymptomatic ones. Therefore, embolus detection monitoring seems a promising tool in the assessment of the individual stroke risk in patients with cardiac embolic sources.
No takes yet. Share an insight, caveat, or question.
Anzola et al. (1995) conducted an observational in Non-valvular atrial fibrillation and prosthetic heart valves (n=86). Prosthetic heart valves and/or atrial fibrillation vs. Healthy subjects and between disease groups was evaluated on Frequency of high intensity transient signals (HITS) per hour (p=0.007). Patients with coexisting prosthetic valves and atrial fibrillation had a significantly higher frequency of cerebral microemboli (12.3/h) compared to those with NVAF (1.4/h, p=0.007) or PV alone.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: