Circulation 2020 Feb 17
Aromatase Inhibitors and the Risk of Cardiovascular Outcomes in Women With Breast Cancer: A Population-Based Cohort Study.
Abstract
Background
The association between aromatase inhibitors and cardiovascular outcomes among women with breast cancer is controversial. Given the discrepant findings from randomized controlled trials and observational studies, additional studies are needed to address this safety concern.
Methods
We conducted a population-based cohort study using the UK Clinical Practice Research Datalink linked to the Hospital Episode Statistics and Office for National Statistics databases. The study population consisted of women newly diagnosed with breast cancer initiating hormonal therapy with aromatase inhibitors or tamoxifen between April 1, 1998, and February 29, 2016. We usedCox proportional hazards models with inverse probability of treatment and censoring weighting to estimate hazard ratios (HRs) with 95% CIs comparing new users of aromatase inhibitors with new users of tamoxifen for each of the study outcomes (myocardial infarction, ischemic stroke, heart failure, and cardiovascular mortality).
Results
The study population consisted of 23 525 patients newly diagnosed with breast cancer, of whom 17 922 initiated treatment with either an aromatase inhibitor or tamoxifen (8139 and 9783, respectively). The use of aromatase inhibitors was associated with a significantly increased risk of heart failure (incidence rate, 5.4 versus 1.8 per 1000 person-years; HR, 1.86 [95% CI, 1.14-3.03]) and cardiovascular mortality (incidence rate, 9.5 versus 4.7 per 1000 person-years; HR, 1.50 [95% CI, 1.11-2.04]) compared with the use of tamoxifen. Aromatase inhibitors were associated with elevated HRs, but with CIs including the null value, for myocardial infarction (incidence rate, 3.9 versus 1.8 per 1000 person-years; HR, 1.37 [95% CI, 0.88-2.13]) and ischemic stroke (incidence rate, 5.6 versus 3.2 per 1000 person-years; HR, 1.19 [95% CI, 0.82-1.72]).
Conclusions
In this population-based study, aromatase inhibitors were associated with increased risks of heart failure and cardiovascular mortality compared with tamoxifen. There were also trends toward increased risks, although nonsignificant, of myocardial infarction and ischemic stroke. The increased risk of cardiovascular events associated with aromatase inhibitors should be balanced with their favorable clinical benefits compared with tamoxifen.
Related Questions
Do you discontinue an aromatase inhibitor in a patient if they have a cardiac event while on the drug?
Randomized clinical trials and several meta-analyses that compared tamoxifen with aromatase inhibitors (Khosrow-Khavar et al., PMID 32065766 is a more recent one) demonstrated statistically significant increase in the rate of cardiovascular events in women taking aromatase inhibitors although the ab...
How would you manage adjuvant endocrine therapy for a postmenopausal patient with early stage HR+ breast CA who develops an ischemic CVA on an AI?
This is a vexing problem that I myself have had to deal with. My patient developed a TIA on aromatase inhibitor (AI). Work up was negative for predisposing risk factors. The choice was easy in this case. This woman was told by her family friend, who was a doctor, that AIs cause stroke and she refuse...