Improving the care of patients with spontaneous coronary artery dissection (SCAD): Are we doing enough?

In this issue of Vascular Medicine, Feldbaum and colleagues evaluate trends in management of spontaneous coronary artery dissection (SCAD) over the course of 14 years (2005–2019) in a ‘real-world’ cohort of 157 patients with SCAD at an academic health system in Pennsylvania. ¹ The most common precipitating factors were physical and emotional stress; ~25% of patients presented with ST-elevation myocardial infarction and ~92% had involvement of a single coronary vessel (most often left anterior descending artery). ¹ Over the course of 14 years, conservative (i.e., medical and noninterventional) management became more common – that is, only 35% of patients were treated conservatively prior to 2013 as opposed to > 85% of patients in 2018 and 2019. ¹ Aspirin and beta-blockers were commonly prescribed throughout the study period. ¹ Importantly, the authors note that conservative management of SCAD became the preferred management strategy after the release of the 2018 American Heart Association (AHA) Scientific Statement on SCAD, which suggests conservative therapy in clinically stable patients with 3–5 days of inpatient monitoring for early complications, such as recurrent myocardial infarction. ² Consideration of revascularization is suggested for those patients with clinical instability or high-risk coronary anatomy (e.g., left main or proximal two-vessel involvement). ² In this current study, patients who underwent revascularization were more likely to have had multivessel SCAD or involvement of the left anterior descending or left main coronary arteries, which suggests that there has been successful diffusion of recommendations from the AHA Scientific Statement and data from other contemporary series into the current inpatient management of SCAD.

Feldbaum and colleagues’ work demonstrates that there has been progress in the understanding of the acute cardiac management of SCAD; however, there remains an opportunity to improve understanding of SCAD as an initial manifestation of a systemic vascular disease. In SCAD registries and case series, full screening for extracoronary vascular abnormalities (EVA; i.e., screening of the cerebral, abdominal, and iliac vasculature) varies from approximately 30% to 88%, depending on the population.^2–4 Among those screened, fibromuscular dysplasia (FMD) was the most common arteriopathy (~35–75% depending on the registry/series). Given the significant coexistence of SCAD and EVA, the AHA Scientific Statement ² recommends brain to pelvis vascular imaging for patients with SCAD, preferably with computed tomography angiography due to its higher spatial resolution compared with magnetic resonance or duplex ultrasonography. Certainly, this must be weighed against radiation exposure, especially as SCAD tends to occur in women of childbearing age.

Despite the above recommendation, Feldbaum and colleagues ¹ show that comprehensive screening for EVAs even in a tertiary academic medical center, is abysmal, with less than 20% of patients with SCAD undergoing comprehensive screening. Partial screening (i.e., imaging of ⩾ 1 vascular territory) was more common, but only reached 71% during the highest period in 2018. Even in patients with at least two cardiology follow-up visits after a SCAD event, comprehensive screening remained exceedingly low. Those undergoing imaging were more likely to have cross-sectional imaging of the abdomen than of the head and neck. Rates of screening with renal or carotid ultrasound remained steady throughout the years, despite the recommendation for cross-sectional imaging rather than ultrasound imaging for initial screening. Not surprisingly, FMD was discovered more commonly in individuals undergoing comprehensive versus partial screening (63% vs 15%). So, why is there such a low rate of comprehensive screening compared to SCAD registries? The authors postulate that in this real-world practice, the patients may not be followed by SCAD experts, especially because the main reason for not undergoing imaging is that the physician did not order the test. Additionally, physicians may be uncomfortable discussing results of imaging with patients due to lack of knowledge regarding FMD or other EVA (e.g., aneurysms, dissections).

Why should we even care about comprehensive extracoronary vascular screening? For example, there are opposing data regarding whether or not presence of FMD in patients in SCAD is associated with a higher risk of long-term cardiovascular adverse events.^5–8 Still, the goal of comprehensive extracoronary vascular screening is to find high-risk abnormalities, such as intracranial aneurysms, arterial aneurysms or dissections, or other abnormalities concerning for heritable connective tissue disorders, such as Marfan, vascular Ehlers–Danlos syndrome, or Loeys–Dietz syndrome. Intracranial aneurysms are found in 7–23% of screened individuals with SCAD.^3,4 In patients with SCAD who undergo genetic testing (with or without EVA), ~5% are found to have a heritable connective tissue disorder. ⁹

So, how do we improve uptake of comprehensive screening rates for EVA in patients with SCAD? It is unlikely that there will be enough SCAD specialists around the US to see every patient. Dissemination of AHA Scientific Statement recommendations does not seem to be the main issue, given the rapid adoption of conservative management of patients with SCAD. ² Exposure of cardiovascular fellows and physicians to comprehensive SCAD care is key. There are now multiple SCAD-related sessions at national cardiology conferences, and multiple review articles have been published in high-impact journals.^3,10,11 Physicians should be empowered to order cross-sectional imaging of the extracoronary vasculature; if abnormal, referral to a vascular specialist can be considered to implement a plan of care for any lesions identified (i.e., aneurysms or dissections of other vessels). Health systems with available programs could include referral to vascular medicine specialists for extracoronary vascular imaging and evaluation for FMD into the care plan for patients with SCAD. Additionally, physicians and hospital systems may consider comprehensive order sets for patients with SCAD; similar to most patients discharged with aspirin and beta-blockers, cross-sectional imaging should be ordered for every patient prior to hospital discharge, which may be completed as either an inpatient or outpatient.

Overall, it is unlikely that one specific action will significantly improve rates of vascular imaging for patients with SCAD; however, multiple congruent actions should hopefully move the needle. Feldbaum et al. show us that we have come far, but still have a long way to go. We must work on improving systems of care for patients with SCAD.