Pregnancy-Linked Dissections: Extremely Rare but ‘Catastrophic’

Arterial dissection occurs in just 0.005% of women who are hospitalized during pregnancy or shortly thereafter, according to nationwide numbers that also provide a snapshot of noteworthy risk factors. These include older age, having had multiple pregnancies, gestational diabetes and hypertension, as well as genetic propensity for connective tissue disorders, study authors say.

Little is known about the true prevalence of such dissections, largely because they are so infrequent, but what is clear is that pregnancy puts “increased stress on the arterial system,” said senior author Brett J. Carroll, MD (Beth Israel Deaconess Medical Center, Boston, MA). To get a more detailed perspective, the researchers turned to the Nationwide Readmissions Database, representing 27 geographically dispersed states and more than half of US residents and hospitalizations.

“As a cardiovascular specialist, I evaluate and manage arterial dissections in the peripartum period so was a bit surprised by how rare these events are,” he told TCTMD via email. “Fortunately the incidence of such events is quite low when reviewed from a population-based level.”

Melinda B. Davis, MD (University of Michigan, Ann Arbor), who has promoted the #CardioObstetrics concept for care, also stressed the rarity of pregnancy-associated dissections. That said, their severity means they merit attention, she commented to TCTMD.

“We always need to remember that these kinds of catastrophic complications can occur,” said Davis. “Even though they’re rare, we don’t want to miss them.” Sudden-onset pain in the first 6 weeks after delivery “should be taken seriously,” she continued. “Clinically, it’s sad to say [but] sometimes women are dismissed and may die at home.” Those women who didn’t go to the hospital weren’t included in the current analysis, Davis pointed out.

Carroll said clinicians should be aware of the risk factors and, when treating patients who have these factors, be attuned to potential arterial dissection when concerning symptoms arise. In terms of timing, “dissections can occur at any time throughout pregnancy, but most occur postpartum,” he noted.

Led by Sebastian E. Beyer, MD (Beth Israel Deaconess Medical Center, Harvard Medical School), the study was published online last week in the European Heart Journal.

Not Always Postpartum

Using the Nationwide Readmissions Database, the researchers looked at more than 18 million women hospitalized for reasons related to pregnancy and/or delivery between 2010 and 2015. Among them, 993 women—or 5.5 out of 100,000—were diagnosed with pregnancy-related dissection. That definition included events that occurred antepartum, during delivery, or within 42 days postpartum.

Beyond having higher prevalence of traditional CV risk factors, the women who developed the arterial dissections tended to be older (32.9 vs 29.0 years), have had more than one pregnancy (3.6% vs 1.9%), and be diagnosed with gestational diabetes (14.3% vs 0.2%), gestational hypertension (6.0% vs 0.6%), and preeclampsia/eclampsia (2.7% vs 0.4%) than those who didn’t have the complication.

On multivariable analysis, independent predictors of dissection included age, chronic hypertension, alcohol use, tobacco use, heart failure, gestational hypertension, and gestational diabetes. Two connective tissue disorders—Marfan syndrome (OR 885.02; 95% CI 309.78-2528.46) and Ehlers-Danlos syndrome (OR 9.36; 95% CI 1.74-50.38)—also stood out as predictive. Obesity, on the other hand, was tied to lower risk.

Arterial dissections happened primarily in the postpartum period (61.5%) but also before (15.1%) and during the admission for delivery (23.4%). Most were coronary (38.2%), followed by vertebral (22.9%), aortic (19.8%), and carotid dissections (19.5%). Before or during delivery, the most common dissections were aortic (41.4%), whereas postpartum, they were coronary (49.6%).

Half of the patients with dissection underwent diagnostic angiography. One in five underwent PCI, most often postpartum, and a similar proportion underwent cardiac surgery. Death occurred at a rate of 3.7% and was only seen in patients with aortic, coronary, or supra-aortic dissections. By comparison, the mortality rate in women without a dissection was < 0.001%.

Connective Tissue Disorders Stand Out

Despite the large size of their data set, there’s still room to learn more, Carroll said. “We do lose some of the specifics like detailed imaging findings and long-term outcomes, which we still need further information on to help best guide management in all arterial dissections. Additionally, understanding further about potential genetic risk factors for patients with peripartum dissections and future risk to the patient and relatives will be interesting.”

Santhi K. Ganesh, MD (University of Michigan), whose research focuses on the genetics of vascular remodeling, observed that the link to Marfan syndrome is notable. “A clinical implication of this finding is that patients with dissection occurring during pregnancy and labor/delivery should be considered for genetic evaluation,” she wrote in an email to TCTMD.

Genetic screening also may be indicated for postpartum dissections, Ganesh said. “Spontaneous coronary artery dissection (SCAD) was the most common type of dissection in the postpartum period, and it is currently estimated that ~5% of patients with SCAD have an underlying ‘monogenic’ genetic diagnosis,” for a disorder caused by variation in a single gene.

Learning more about how to identify at-risk women is key, Davis said, and patients should know their own family history, especially in relation to connective tissue disorders, chronic hypertension, or diabetes. Given how rare arterial dissections are, “women shouldn’t be scared to be pregnant but should advocate for themselves if they do have anything concerning,” she advised.

More broadly, Davis said attention to cardiovascular health in relation to pregnancy is growing and that an American College of Cardiology task force on cardio-obstetrics is in the works. “It really is an area that we can embrace as needing some subspecialized care,” she added.