Overview
Women with chronic severe coronary artery disease face a major treatment decision when blood flow to the heart needs to be restored: percutaneous coronary intervention, or PCI, versus coronary artery bypass grafting, or CABG. PCI is the less invasive option, usually performed with a catheter and stent placement through an artery in the wrist or groin. CABG is open-heart surgery that creates new routes for blood to reach the heart muscle using graft vessels.
Although both approaches are widely used, most earlier studies have not focused specifically on women, even though women often have different symptom patterns, vessel size, comorbidity profiles, and procedural risks than men. This study used real-world data from Ontario, Canada, to compare long-term outcomes after PCI and CABG in women with chronic severe coronary artery disease.
Why this study matters
Coronary artery disease remains a leading cause of illness and death in women. Yet women have historically been underrepresented in cardiovascular trials, especially in studies comparing revascularization strategies. As a result, treatment decisions have often relied on data dominated by male participants or mixed-sex populations, which may not fully reflect women’s outcomes.
This study helps address that gap by examining a large cohort of women in routine clinical practice over nearly a decade. The findings are especially important because they look beyond short-term procedural safety and focus on long-term events such as death, heart attack, stroke, and repeat procedures.
Study design and methods
The investigators conducted a propensity score-matched retrospective cohort study using linked clinical and administrative databases in Ontario, Canada. Women with chronic severe coronary artery disease who underwent either PCI or CABG between 2012 and 2021 were identified.
Propensity score matching is a statistical method used to make two treatment groups more comparable. It attempts to balance factors such as age, comorbidities, and illness severity so that differences in outcomes are less likely to be explained by baseline differences alone. In this study, 2,469 women underwent PCI and 3,721 underwent CABG, and after matching, 2,033 well-balanced pairs remained for analysis.
The main outcome was major adverse cardiovascular and cerebrovascular events, commonly abbreviated as MACCE. This composite endpoint included:
– All-cause death
– Myocardial infarction, or heart attack
– Stroke
– Repeat revascularization
The researchers also examined each component separately and looked at cardiovascular readmissions, defined as hospital readmission for myocardial infarction, heart failure, or stroke. Time-to-event outcomes were analyzed with Cox proportional hazards models, a standard method for comparing event rates over time.
Key findings
The average age of the matched patients was 66.5 years, with a standard deviation of 8.6 years, meaning many women were in their mid-60s but there was a wide age range.
At a median follow-up of 5.1 years, PCI was associated with worse long-term outcomes than CABG.
Major findings included:
– MACCE occurred more often after PCI than after CABG: hazard ratio 1.81, 95% confidence interval 1.63 to 2.01, P < .001
– All-cause mortality was higher after PCI than after CABG: hazard ratio 1.34, 95% confidence interval 1.16 to 1.54, P < .001
– Cardiovascular readmission was also higher after PCI than after CABG: hazard ratio 1.40, 95% confidence interval 1.32 to 1.49, P < .001
These results suggest that, in this population, CABG offered better long-term protection against major cardiovascular and cerebrovascular complications.
How to interpret the results
A hazard ratio above 1 means the event happened more often in the PCI group than in the CABG group. For example, the MACCE hazard ratio of 1.81 indicates that women treated with PCI had an 81% higher risk of the combined outcome over the follow-up period compared with women treated with CABG, after statistical adjustment.
The difference in mortality is clinically important. While PCI is often favored because it is less invasive, requires a shorter recovery, and is associated with lower immediate surgical trauma, this study suggests that the long-term trade-off may favor CABG for appropriately selected women with severe chronic disease.
The higher rate of cardiovascular readmission after PCI also points to a greater likelihood of recurrent ischemic events, heart failure-related hospitalization, or stroke. In practical terms, CABG may provide more durable revascularization in women with advanced coronary disease.
Why CABG may perform better in severe disease
CABG can bypass multiple blocked or narrowed arteries and may be especially beneficial when coronary disease is diffuse, complex, or involves several major vessels. By creating new blood flow routes beyond the diseased segments, surgery may reduce the chance of future ischemic events and the need for repeat procedures.
PCI, on the other hand, is highly effective for many patients, particularly when disease is limited to one or a few lesions. However, in more complex disease, stents may not fully address the underlying burden of atherosclerosis. Women may also have smaller coronary arteries on average, which can make PCI technically more challenging and may contribute to restenosis or future reintervention in some cases.
It is important to emphasize that the best treatment depends on the individual patient. Coronary anatomy, frailty, diabetes, kidney function, heart failure, prior stroke, and patient preference all matter. CABG is not automatically better for every woman, but this study adds evidence that it may be the preferred strategy when anatomy and surgical risk are favorable.
Clinical implications for women
For women with chronic severe coronary artery disease, this study supports a more careful discussion of the expected long-term benefits and risks of each revascularization strategy. A less invasive procedure is not always the best long-term option. If the disease is extensive or anatomically complex, CABG may offer superior durability and fewer major events over time.
This does not mean PCI should be abandoned in women. PCI remains appropriate in many situations, including acute coronary syndromes, patients who are not good surgical candidates, or cases where the coronary disease pattern is suitable for catheter-based treatment. However, when both PCI and CABG are technically feasible, the findings here suggest that CABG deserves strong consideration.
Shared decision-making is essential. Women should be informed not only about immediate recovery time and procedural invasiveness, but also about the likelihood of future heart attacks, strokes, repeat procedures, and hospitalizations.
Strengths and limitations
This study has several strengths. It included a large, real-world population of women over a long follow-up period, and it used propensity score matching to reduce baseline differences between treatment groups. It also evaluated meaningful clinical outcomes rather than relying only on short-term procedural success.
However, as an observational study, it cannot prove causation. Even with matching, unmeasured factors may have influenced treatment choice and outcomes. For example, details about coronary anatomy, symptom burden, frailty, left ventricular function, and some procedural nuances may not have been fully captured in administrative data. In addition, results from one Canadian province may not apply perfectly to other health systems or patient populations.
Another point is that CABG patients may sometimes be selected because they have more complex disease, which would usually bias the results against surgery. Despite that, CABG still showed better long-term outcomes in this analysis, which strengthens the practical importance of the findings.
Bottom line
In women with chronic severe coronary artery disease, CABG was associated with lower long-term rates of major adverse cardiovascular and cerebrovascular events, lower mortality, and fewer cardiovascular readmissions than PCI. These findings suggest that CABG should be strongly considered as the preferred revascularization strategy in appropriately selected women, especially when disease is extensive or complex.
The study also highlights the need for more sex-specific cardiovascular research so that women receive treatment recommendations based on evidence that truly reflects their outcomes.