Hypothyroidism in spontaneous coronary artery dissection: presentation, clinical and angiographic findings, management and outcomes

Abstract

Background: Hypothyroidism has been suggested as a predisposing and prognostic factor in patients with spontaneous coronary artery dissection (SCAD), but evidence in this regard is very limited. Methods: This study sought to compare differences in clinical presentation, angiographic findings, management and outcomes between SCAD patients with (H-SCAD) and without (NH-SCAD) a history of hypothyroidism from the prospective nation-wide Spanish SCAD Registry. Results: Overall, 47 H-SCAD (12%) and 342 NH-SCAD patients were included. H-SCAD patients when compared with NH-SCAD patients were significantly older (57±10 vs 54±12 years, p=0.045), had more frequent dyslipidaemia (49% vs 31%, p=0.013) and a non-significant trend to more associated fibromuscular dysplasia (47% vs 30%, p=0.191). Clinical presentation did not differ between groups, with non-ST-segment elevation myocardial infarction being the more frequent diagnosis at admission (62% vs 53%, p=0.273). H-SCAD patients showed more frequent multivessel involvement (19% vs 9%, p=0.044), angiographic type 2b lesions (36% vs 23%, p=0.037), lesions at segments with side-branches (68% vs 52%, p=0.026) and tighter lesions (88±13% vs 77±21% diameter stenosis, p=0.001), but less involvement of proximal segments (5% vs 15%, p=0.044). Revascularisation was more commonly needed in H-SCAD patients (34% vs 20%, p<0.05). At late clinical follow-up (median 29 months), the H-SCAD group had a higher adverse event rate (27% vs 11%, p=0.033), mainly driven by myocardial infarction (16% vs 6%, p=0.031) and SCAD recurrence (9% vs 1%, p<0.001). On multivariable analysis, the presence of hypothyroidism remained independently associated with adverse clinical events. Conclusions: H-SCAD patients were older and had a more diffuse and aggressive angiographic phenotype, including type 2b lesions, tighter lesions and more frequent multivessel involvement. Revascularisation was more frequently needed in H-SCAD patients. Long-term outcomes were poorer in this group, mainly driven by myocardial infarction and SCAD recurrence.