MedWire News: Subarachnoid hemorrhage (SAH) patients are at elevated risk for dying within 3 months of aneurysm surgery if they have pre-operative electrocardiographic (ECG) abnormalities, reveals US research.
The Intra-operative Hypothermia Aneurysm Surgery Trial (IHAST) substudy findings show that the risk for postoperative mortality is strongly increased in patients with bradycardia, relative tachycardia, or nonspecific ST- and T-wave abnormalities.
“Therapeutic options for patients with SAH that affect heart rate should be reassessed,” say Jonathan Zaroff (Kaiser San Francisco Medical Center, California) and colleagues.
They say that beta blockers, for example, may limit relative tachycardia, but could conversely lead to bradycardia and increased mortality. “Further clinical research in this area is required,” they stress.
The IHAST ECG substudy included only patients who underwent aneurysm surgery within 4 days of SAH onset and had pre-operative ECG findings available. Thirty-one (5%) of these 588 patients died within 3 months of surgery.
ECG abnormalities were very common, being present in 80% of the cohort. Nonspecific ST- and T-wave abnormalities were most common, occurring in 62% of patients with abnormalities. These were associated with 3.1-fold rise in the risk for dying within 3 months of surgery.
Bradycardia was present in 21% of patients, and was associated with a 6.1-fold increase in mortality risk (heart rate ≤60 vs 61–70 beats per min [bpm]). Tachycardia, which was identified in 5% of patients, was associated with an 8.8-fold rise in death risk (81–138 vs 61–70 bpm).
The researchers also found a nonsignificant association between prolonged corrected QT interval (QTc) and postoperative mortality.
“Patients with markedly prolonged QTc should probably be followed with increased vigilance for the development of cardiovascular instability,” they suggest in the journal Stroke.
The team also observes: “It is notable that aneurysm size and location, Fisher Scale, and National Institutes of Health Stroke Scale were not significantly associated with mortality, suggesting that the ECG findings may actually have greater prognostic value than many of the more standard clinical measures.”
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