Clinical Implications of the “Broken Line” Angiographic Pattern in Patients With Spontaneous Coronary Artery Dissection

Spontaneous coronary artery dissection (SCAD) is a rare but increasingly recognized cause of acute myocardial infarction. Coronary angiography remains the best diagnostic tool; however, clinical suspicion and experience is required to interpret angiographic findings. This study sought to assess the clinical implications of the "broken line" (BKL) angiographic pattern in a large, nationwide, cohort of patients with SCAD. The Spanish SCAD registry (NCT03607981) prospectively enrolled consecutive patients with SCAD. All angiograms were centrally analyzed and the BKL pattern was systematically assessed. The BKL angiographic pattern was found in 64 of 389 patients (16%). Patients with the BKL appearance were more frequently female (97 vs 87%, p <0.05), presented more often as intramural hematoma (83 vs 58%, p <0.001), had longer lesions (47 ± 29 vs 36 ± 22 mm, p <0.01), and had severe tortuosity (25 vs 10%, p <0.01) but showed better initial coronary flow (thrombolysis in myocardial infarction flow 2.6 ± 0.8 vs 2.1 ± 1.2, p <0.01). Patients with BKL received more frequently conservative medical management (91 vs 76%, p <0.01). At late clinical follow-up (median 29 months, interquartile range 17 to 38) predefined adverse events (death, myocardial infarction, revascularization, recurrent SCAD, or stroke) occurred less frequently (3.5 vs 15%, p <0.05) in patients with the BKL appearance. The better clinical outcomes of patients in the BKL group persisted after adjusting for potential confounders (adjusted hazard ratio 0.2, 95% confidence interval 0.1 to 0.9, p <0.05). In conclusion, patients with SCAD presenting the BKL angiographic pattern are more frequently female and present more often as intramural hematoma with longer lesions and severe vessel tortuosity but have better coronary flow. Patients with the BKL morphology have a favorable prognosis (NCT03607981).