Though more men than women suffer from aortic dissection, an uncommon but deadly tear in the body's largest artery, a sweeping new analysis of almost 3,000 patients has found that women are more likely to die from this condition, likely because they tend to get treatment later.
Aortic dissection occurs when the inner layer of the aorta tears. And while the condition is relatively rare, occurring in about 30 people per million, it extremely dangerous. Because blood in the aorta is under a lot of pressure, a tear in the inner lining triggers an influx of blood that can separate the other layers of the aortal lining, eventually bursting through the outer wall into the body cavity, which is generally fatal.
The new study, published June 2 in the Annals of Thoracic Surgery, also found that women who suffer aortic dissection tend to be older than men, but this did not appear to be the main reason it tends to prove more deadly. Broadly, the research emphasizes gender disparities in cardiovascular health outcomes that permeate our health care system.
"If you track [aortic dissection] outcomes in women compared to men over the last decade, there has been an improvement in outcomes for women, but mortality outcomes still remain worse," said principal investigator Tom Gleason, a cardiac surgeon at Brigham and Women's Hospital.
While the condition is uncommon, there have been several fatal cases in well-known celebrities. Actress and comedian Lucille Ball, star of I Love Lucy, died from complications of aortic dissection in 1989 at the age of 77. And the first-ever documented case occurred in King George II of England, who died from an aortic dissection in 1760.
"It's a highly lethal cardiovascular phenomenon that occurs in a small but significant percentage of the population," said Gleason, who went on to explain that aortic dissection has an increasing mortality rate of about 1% for every hour that it goes untreated, so within a few days, the mortality rate spikes to almost 50%. This is only if the dissection is not instantly fatal, which happens in up to 40% of cases.
The role that sex plays in outcomes for aortic dissection is debated. While most studies agree that more men are diagnosed with aortic dissection than women, some previous studies have concluded that there is no evidence suggesting that women experience greater mortality from aortic dissection than men.
The present study adds to this debate with data from the International Registry of Acute Aortic Dissection, a consortium of research centers that collect and catalogue detailed data on aortic dissection, including time of symptom onset, presentation and what imaging and treatments were administered. Gleason himself is a senior leader of this consortium, so he and his colleagues had ready access to the data.
They focused on a group of 2,823 patients who experienced aortic dissection from 1996 to 2018 and underwent surgery for their condition, either exclusively or as part of a hybrid treatment. Approximately 34% of the patients were female. These women were typically much older than men diagnosed with aortic dissection, with an average age of 65.4 years for women in the study compared to 58.6 years for men.
And though there were fewer women with the condition, their mortality rate was higher, 16.7% compared to 13.8% in men.
The team also noted differences in the presentation of symptoms in women, such as a greater likelihood of blood leaking between the layers of the aortic wall and creating space in which blood can clot, as well as a higher prevalence of shock or comas.
Gleason pointed out that the drivers of disparities in mortality could be attributed to a combination of social and physical factors, as women may seek treatment later than men and their symptoms may be misinterpreted by doctors and emergency room staff.
"The recognition that women present differently and later in the course suggests that they may be seeking emergency care in a more delayed fashion than men," Gleason said. "Accordingly, clinicians should respond to these sometimes opaque signs and symptoms by considering aortic dissection early … We should be hypervigilant in women to avoid any further delays in treatment."
When the condition is caught and treated appropriately, the researchers found, there is little difference in long-term survival between men and women, suggesting that the key issue at play is catching the disease in women early enough to treat them adequately.
"It appears there may be some bias, perhaps in prehospital and in the emergency room, toward men [and against] women in facilitating the diagnosis," Gleason said. "Once the diagnosis is made, the treatment cascade is going to be similar, but it's getting to that point."
In future studies, the researchers plan to investigate drivers of aortic dissection and related conditions in each sex more thoroughly. They also hope they can use their database to answer more questions about how aortic dissection outcomes are distributed across different demographics.
"This is an excellent example of the utility of these large registries," Gleason said. "The database and the registry itself can be leveraged to answer more questions like this, as it's grown over the many years it's been in existence."
The study, "Sex-based aortic dissection outcomes from the International Registry of Acute Aortic Dissection," published June 2 in the Annals of Thoracic Surgery," was authored by Lauren V. Huckaby and Ibrahim Sultan, University of Pittsburgh Medical Center; Santi Trimarchi, Università degli Studi di Milano; Bradley Leshnower and Edward P. Chen, Emory University School of Medicine; Derek R. Brinster, Northwell Health; Truls Myrmel, Arctic University of Norway; Anthony L. Estrera, UT Medical School Houston, Daniel G. Montgomery, Kim A. Eagle and Himanshu J. Patel, University of Michigan; Amit Korach, Hadassah Medical Center; Hans-Henning Eckstein, Technische Universität München; Joseph S. Coselli, Baylor College of Medicine; Takeyoshi Ota, University of Chicago; Clayton A. Kaiser, Saint Thomas Heart; and Thomas G. Gleason, Brigham and Women's Hospital.