Does the Canadian Syncope Risk Score identify patients at low risk of cardiac abnormality in whom TTE is unnecessary among general medicine patients presenting with syncope or presyncope?
Using the Canadian Syncope Risk Score to stratify risk in general medicine patients with syncope or presyncope can safely identify low-risk patients and potentially halve the use of transthoracic echocardiography.
STUDY PURPOSE: Routine transthoracic echocardiography (TTE) in patients with syncope or presyncope is resource-intensive. We assessed if risk thresholds defined by a validated risk score may identify patients at low risk of cardiac abnormality in whom TTE is unnecessary. STUDY DESIGN: We conducted a retrospective study of all general medicine patients with syncope/presyncope presenting to a tertiary hospital between July 2016 and September 2020 and who underwent TTE. The Canadian Syncope Risk Score (CSRS) was used to categorise patients as low to very low risk (score -3 to 0) or moderate to high risk (score ≥1) for serious adverse events at 30 days. A cut-point of 0 was used to calculate the sensitivity, specificity, positive and negative predictive values (PPV and NPV) for CSRS and the odds ratio (OR) of a clinically significant finding on TTE in patients with CSRS ≥1 compared with all patients. RESULTS: Among 157 patients, the CSRS categorised 69 (44%) as very low to low risk in whom TTE was normal. In 88 patients deemed moderate to high risk, TTE detected a cardiac abnormality in 24 (27%). A CSRS ≥1 yielded a sensitivity of 100% (95% CI 85.7% to 100%), specificity of 51.1% (95% CI 42.3% to 59.8%), PPV of 26.5% (95% CI 26.3% to 30.1%) and NPV of 100% (95% CI 92.5% to 100%) for cardiac abnormalities and doubled the odds of an abnormality (OR = 2.05, 95% CI 1.08 to 3.87, p = 0.028). CONCLUSION: In general medicine patients with syncope/presyncope, using the CSRS to stratify risk of a cardiac abnormality on TTE can almost halve TTE use.
Simos et al. (Tue,) studied this question.