CV risk elevated following cancer diagnosis

Patients newly diagnosed with cancer have an increased risk of cardiovascular (CV) events including CV mortality, according to a retrospective population-based study from Canada.

“[W]e found that a new diagnosis of cancer was associated with an increased risk for fatal and non-fatal CV events, even after adjustment for baseline risk,” the researchers said.

The study population comprised 4,519,243 adults who resided in Alberta, Canada, between April 2007 and December 2018, according to administrative healthcare databases. The participants were followed up for a median 11.8 years, during which time 224,016 individuals were newly diagnosed with cancer. A total of 73,360 CV deaths and 470,481 non-fatal CV events also occurred during this time frame. Patients diagnosed with cancer between April 2004 and study onset were excluded.

The median age of cancer patients and non-cancer controls was 56 and 34 years, respectively, and 56.8 and 48.5 percent, respectively, were female. At baseline, 24 and 22 percent, respectively, had dyslipidaemia, 31.7 and 10.7 percent, respectively, had hypertension, 17.1 and 11.2 percent, respectively, had severe obesity, and 10.1 and 3.6 percent, respectively, had diabetes. Common non-CV comorbidities were chronic pain (15.1 and 7.9 percent, respectively) and chronic obstructive pulmonary disease (10.1 and 3.5 percent, respectively).

The most common cancers were gynaecological, genitourinary, gastrointestinal, and breast cancer (20.3, 19.3, 16.5, and 13.1 percent, respectively).

The risk of CV mortality was increased in individuals with vs without cancer (adjusted hazard ratio [adjHR], 1.33, 95 percent confidence interval [CI], 1.29–1.37). [J Am Coll Cardiol CardioOnc 2022;4:85-94]

Patients with cancer also had an increased risk for stroke (adjHR, 1.44, 95 percent CI, 1.41–1.47), heart failure (HF; adjHR, 1.62, 95 percent CI, 1.59–1.65), and pulmonary embolism (PE; adjHR, 3.43, 95 percent CI, 3.37–3.50), and a slightly elevated risk of acute myocardial infarction (MI; adjHR, 1.01, 95 percent CI, 0.97–1.05) than those without cancer.

The results were consistent after excluding patients aged <50 years and those diagnosed with stage 0 cancer. After matching for age and sex, the risk of CV mortality in cancer patients vs non-cancer controls increased (from HR, 1.33 to 1.73), as did the risk of all-cause mortality (from HR, 8.34 to 12.92). The risks for all outcomes (except MI) were greater in patients who were younger vs older at cancer diagnosis.

The risks for CV mortality, PE, HF, and stroke were higher compared with individuals without cancer for all cancer sites except melanoma. The risk for CV events was greatest in patients diagnosed with genitourinary, gastrointestinal, thoracic, nervous system, or haematologic cancers, with patients with these cancers comprising 55 percent of the cancer cohort and >71 percent of the CV burden.

The increased risk of any of the CV events was also greatest in the first year after cancer diagnosis (HR, 1.24–8.36). While the risk generally reduced over time, the risk for CV mortality, HF, and PE remained significantly elevated after 10 years of follow-up. The risk was also consistently elevated regardless of cancer stage but was particularly high among patients diagnosed at a more advanced stage of cancer.

The increased risk of CV mortality and non-fatal CV events in the first year post-cancer diagnosis “suggests that patients with cancer may benefit from co-management that includes cardiologists as well as stroke and thrombosis specialists,” the researchers pointed out.

They acknowledged that some factors that influence CV disease and cancer such as cancer treatments, smoking, and physical activity were not accessible.

“[O]ur study shows that patients with prior cancer are susceptible to a variety of CV events over a long time frame. Unfortunately, this risk is unlikely to diminish in the short term given that many newer cancer therapies are also associated with increased risk for myocardial injury and HF,” they said.

“Future studies should evaluate other potential contributors to CV risk, including cancer therapies and emerging risk factors of cardiotoxicity,” the researchers concluded.