Head-up tilt testing in older syncope patients: a systematic review

Background In older syncope patients, medical histories are often less reliable due to retrograde amnesia and cognitive impairment. Therefore, additional tests may be needed to reach a diagnosis. We conducted a systematic review to evaluate positivity rates and safety of head-up tilt testing (HUTT) in these patients. Methods We searched Medline and Embase for HUTT positivity rates and diagnoses in older syncope patients (mean age ≥ 65 years) vs. younger patients. Secondary outcomes were time to syncope (TtS) and adverse events (AEs). Risk of bias was assessed with a modified version of the QUADAS-2. Results In total, 42 studies were included, with 12 378 older participants in total. Positivity rates varied widely [passive HUTT 0.0%–90.0%; isoproterenol (IPR)-HUTT 18.3%–64.0%; nitroglycerin-HUTT 30.1%–90.5%]. The majority of studies found no differences between older and younger patients. Specificity was high for all HUTT-protocols (85.5%–100%). TtS did not differ between older and younger patients, but was significantly longer in control subjects. Nitroglycerin-HUTT yielded the most diagnoses (median 64.2% vs. 23.7% for passive, P = .007, and 44.8% for IPR-HUTT, n.s.). Vasodepressive responses were more common than cardioinhibitory responses (median 54.9% vs. 9.1%) in older patients. AEs occurred in <6% of patients with passive/nitroglycerin-HUTT. Discussion/conclusion There is no consistent evidence that HUTT results differ between older and younger syncope patients. Nitroglycerin-HUTT yields the most diagnoses, whilst retaining a high specificity, and is safe to perform in older patients. Future studies should focus on the additional value of HUTT on top of the initial evaluation in these patients.