The Diagnostic Value of ECG Characteristics for Vasospastic and Microvascular Angina: A Systematic Review

Background: Coronary vascular dysfunction comprises VSA and/or MVA and is more common in women than in men with angina without obstructive coronary artery disease (ANOCA). Invasive coronary function testing is considered the reference test for diagnosis, but its burden on patients is large. We aimed to investigate the potential of electrocardiography (ECG) as noninvasive marker for vasospastic angina (VSA) and microvascular angina (MVA) diagnosis.

Methods: We systematically screened Pubmed and EMBASE databases for studies reporting on ECG characteristics in ANOCA patients with (a suspicion of) coronary vascular dysfunction. We assessed study quality using QUADAS-2. We extracted data on diagnostic values of different ECG characteristics and analyzed whether the studies were sex-stratified.

Results: Thirty publications met our criteria, 13 reported on VSA and 17 on MVA. The majority addressed repolarization-related ECG parameters. Only 1 of the 13 VSA papers and 4 of the 17 MVA papers showed diagnostic accuracy measures of the ECG characteristics. The presence of early repolarization, T-wave alternans, and inverted U waves showed of predictive value for VSA diagnosis. The QTc interval was predictive for MVA diagnosis in all six studies reporting on QTc interval. Sex-stratified results were reported in only 5 of the 30 studies and 3 of those observed sex-based differences.

Conclusions: ECG features are not widely evaluated in diagnostic studies for VSA and MVA. Those features predictive for VSA and MVA diagnosis mostly point to repolarization abnormalities and may contribute to noninvasive risk stratification.