Although cardiovascular disease (CVD) is known to often strike the mortal blow in patients with cancer, a national analysis puts in stark relief the burden of CV-related hospitalizations in this vulnerable population.
Results show that between 2004 and 2017, CV admissions increased 23.2% among patients with a cancer diagnosis, whereas admissions fell 10.9% among those without cancer.
Admissions increased steadily across all cancer types, except prostate cancer, with heart failure being the most common reason for admission.
“Hospital admissions is really important because we know that the size of this group is increasing, given that they live longer and many of the treatments that we offer cause cardiovascular disease or increase the risk of having cardiovascular events. So, from a healthcare planning perspective, I think it’s really important to see what the burden is likely to be in the next few years,” senior author Mamas Mamas, MD, Keele University, England, told theheart.org | Medscape Cardiology.
For physicians and the wider population, he said, the findings underscore the need to shift the conversation from saying that patients with cancer are at increased CVD risk to asking how to mitigate this risk. “Because I would say that this increase in cardiovascular admissions, that’s a failure from a preventative perspective.”
The study was published August 1 in the European Heart Journal: Quality of Care & Clinical Outcomes.
Individual Cancer Types
The researchers, led by Ofer Kobo, MD, also with Keele University, used the National Inpatient Sample to identify 42.5 million weighted cases of CV admissions for acute myocardial infarction (AMI), pulmonary embolism, ischemic stroke, heart failure, atrial fibrillation (AF), or atrial flutter and intracranial hemorrhage from January 2004 to December 2017. Of these, 1.9 million had a record of cancer.
Patients with cancer were older; had a higher prevalence of valvular disease, anemia, and coagulopathy; and a lower prevalence of hypertension, diabetes mellitus, and obesity than did patients without cancer.
The most common cancer type was hematologic cancers (26.1%), followed by lung (18.7%), gastrointestinal (12.4%), prostate (11.6%), breast (6.7%) and other in 24.4%.
The admission rate increased across all six admission causes — between 7% for AMI and ischemic stroke and 46% for AF.
Heart failure was the chief reason for admission among all patients. Annual rates per 100,000 US population increased in patients with cancer (from 13.6 to 16.6; P for trend = .02) and declined in those without (from 352.2 to 349.8; P for trend < .001).
“In the past, patients would be started on medications and perhaps the importance of monitoring [left ventricular] LV function wasn’t as widely known, whereas now we’re much more aggressive in looking at it and much more aggressive at trying to prevent it,” Mamas said. “But even with this greater identification and attempting to modify regimens, we’re still getting quite substantial increases in heart failure admissions in this population. And what really surprised me is that it wasn’t just in the breast cancer population, but it was nearly across the board.”
He noted that patients are at highest risk from CV events within the first 2 years of cancer diagnosis. “So that’s really the time where you’ve got to be really aggressive in looking and working up their cardiovascular profile.”
Patients with hematologic cancers (9.7-13.5), lung (7.4- 8.9), and gastrointestinal cancer (4.6-6.3) had the highest crude admission rates of CV hospitalizations per 100,000 US population.
The CV admission rate went up from 2.5 to 3.7 per 100,000 US population for breast cancer, and in prostate cancer, the rate dropped from 5.8 to 4.8 per 100,000 US population.
Of note, patients with hematologic cancers also had the highest rate of heart failure hospitalization across all cancer types, which, coupled with their increasing admission rates, likely reflects their exposure to a “constellation of cardiotoxic therapies” as well as pathologic processes related to the cancers themselves, the authors suggest.
In-hospital mortality rates were higher among patients with cancer than those without, ranging from 5% for patients with breast cancer to 9.6% for patients with lung cancer vs 4.2% for those without cancer.
Among patients with cancer, the odds ratio for mortality was highest in those admitted with AF (4.43), followed by pulmonary embolism (2.36), AMI (2.31), ischemic stroke (2.29), and heart failure (2.24).
In line with prior work and general population trends, in-hospital deaths in primary CV admissions trended lower among patients with cancer over the study period.
Commenting on the study, Joerg Herrmann, MD, director of the cardio-oncology clinic at Mayo Clinic in Rochester, Minnesota, said that the data are “extremely important” because they reflect admissions during a new era of cancer therapy. “Targeted therapies all came out about the turn of the millennium, so we’re not really looking at cancer patients treated with only old and ancient strategies.”
This may be one reason for the increased admissions, but because the study lacked information on specific cancer treatments and the date of cancer diagnosis, it’s not possible to tease out whether the uptick is related to cardiotoxicity or because the oncology outcomes have improved so much that this is a growing population, he said.
One clear implication, however, is that whoever is working on the hospital service will see more patients with a cancer diagnosis, Herrmann observed.
“Though some may have tried to maybe not get involved with this topic as much, it really calls for some broader scope to get familiar with this very entity,” he said. “And that plays out, in particular, in those patients with a diagnosis of active cancer.”
Herrmann and colleagues previously reported that patients with active leukemia or lymphoma who were hospitalized with acute coronary syndrome were less likely to receive guideline-directed therapies, even at the Mayo Clinic.
Similarly, a 2020 report by Mamas and colleagues found that patients with a variety of active cancers derived similar benefit from primary percutaneous coronary intervention for ST-segment–elevation MI as those without cancer, but received the treatment less commonly.
Although there’s a greater appreciation that patients with cancer benefit equally from aggressive treatment, much more can be done to mitigate CV risk, Mamas noted. Valuable coronary information captured by MRI and CT done as part of the cancer investigation is often overlooked. For example, “we know that breast calcification and vascular calcification in the breast are very strong predictors of cardiovascular outcomes and yet people aren’t using this information.”
There are numerous shared risk factors in the development of cancer and coronary artery disease, and patients with cancer often have much worse CV risk profiles but aren’t routinely risk stratified from a CV perspective, he said.
Mamas said that his team is also studying whether CVD risk prediction tools like the Framingham Risk Score, which were derived from noncancer populations, work as well in patients with cancer. “Often, when you look at the performance of these tools in populations that weren’t covered, they’re much worse.”
“A lot of cancer survivors worry about the recurrence of their cancer and will religiously go and have repeated scans, religiously check themselves, and have all these investigations but don’t think about the actual risk that is greater for them, which is cardiovascular risk,” he said.
The authors report no study funding or relevant financial relationships.
Eur Heart J Qual Clin Outcomes. Published online August, 1 2022. Abstract