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.