Among cancer patients with tachycardia but without a health problem associated with tachycardia, such as lung disease or thyroid disease, the overall mortality risk is significantly increased. According to US researchers, this increased risk may reflect the additional strain imposed on the body by cancer.

Tochi M. Okwuosa, DO, director of the cardio-oncology program at the Rush University Medical Center in Chicago, Illinois, has studied more than 620 cancer patients, 50 of whom had explained the problem. Existence of sinus tachycardia.

After taking into account many potential confounding factors, the researchers found that in cancer patients with tachycardia, the overall mortality risk was about three times higher than that of other cancer patients.

The results were presented at the Oncology Cardiovascular Patient Conference on January 25th.

The co-author of the study, Mohamad Hemu, also said in a statement: "Tachycardia is a process secondary to an underlying disease and reflects an important multi-system organ stress and disease in the cancer patients.

"As a result, the most important initial step is to determine the cause of tachycardia," he continued. "Reversible causes such as dehydration and infections should be excluded." In addition, cardiopulmonary processes such as pulmonary embolism and other arrhythmias must be taken into account.

"Once these causes and all other causes of tachycardia are eliminated, then it is more likely that sinus tachycardia is a marker of a worse prognosis in these patients," commented Hemu.

Okwuosa said his study "shows that tachycardia is a powerful prognosis, no matter what type of cancer," while demanding more studies.

Tachycardia is a powerful prognosis, regardless of the type of cancer.
Dr. Tochi Okwuosa

"That's why it's essential to jointly manage cancer and heart disease so that patients receive the most effective treatment possible."

Sending to Medscape Medical News, Okwuosa explained that their hypothesis was that tachycardia reflected the metabolic strain imposed on the patient's system by cancer.

By analogy, she said that when healthy people run, their heart rate goes up and they actually become tachycardias.

"Generally, what happens is that your body is accelerating your heart rate to provide more blood to your tissues as you run because your tissues need this blood flow," she said. .

"Well, at someone who is very sick and has a systemic problem that affects his whole body, like cancer, I feel sicker, the more their cells are affected, the more the rest of the body is affected, and therefore more demand to try to meet the metabolic needs of cancer is high. "

Okwuosa said that pending the results of other studies on the efficacy of beta-blockers in the treatment of unexplained tachycardia in cancer patients, "one of the last questions is what kind of advice do you have? for patients with tachycardia and who are undergoing cancer treatment?

"In all honesty, it is difficult to determine what is the right answer.Do you tell the patient that this suggests that you are really sick and that this suggests that there is a good chance that you will die?"

"No, I think most of us would not do that, especially since there is new data coming out," she said.

On the other hand, Okwuosa suggested that even if cancer patients are not able to do the recommended 150 minutes of exercise per week, they should try to walk or bike as much as possible to revitalize their bodies.

"We know that in normal patients, the more you exercise, the slower the heart rate, because vagal tone is increased, but it is increasingly difficult to advise cancer patients, simply because they are really sick, "she said. .

"But we always encourage them to get conditioned," she added.

Gordon F. Tomaselli, a medical doctor at the Albert Einstein College of Medicine in New York, said that once the main causes of tachycardia are eliminated, "I really think you have to look closely at the heart for sure there is no potential complication that can worsen and at least be treated. "

"It's not at all surprising to me … that unexplained tachycardia is an unfavorable predictor of the outcome, and that several reasons can explain it."

Tomaselli pointed out that it was "more and more important" that when a cancer patient is about to start a treatment, you make sure you understand the underlying state of his heart. and his ships.

"Nobody will thank you if you have an effective treatment for cancer, but it leaves you with a very important cardiovascular disease that will limit your life expectancy and, more importantly, can make the morbidity of treatment pretty high every day", he added.

Details of the study

Okwuosa and colleagues conducted a retrospective case-control analysis of 622 patients with lung cancer, leukemia, lymphoma, or multiple myeloma who underwent treatment from 2008 to 2016.

Tachycardia was defined as a heart rate ≥100 bpm at three or more clinical visits in the year following the diagnosis of cancer.

After excluding patients with a history of pulmonary embolism, thyroid dysfunction, ejection fraction <50%, atrial fibrillation/ flutter, and heart rate> 180 bpm, they identified 50 patients with unexplained tachycardia and 572 control patients.

Of the 622 cancer patients included in the study, the average age was 70, 60.5% female and 76.4% white.

Of all cancer patients, 69.4% had stage IV cancer of the US Joint Committee on Cancer and 43.0% had lung cancer.

After adjustment for age, race, albumin, hemoglobin, beta-blockers, kidney disease (defined as a glomerular filtration rate <60 ml / min), anticoagulant therapy, and a type of cancer, the team found that an initial heart rate ≥ 100 bpm predicted overall mortality at a risk of 3.1 (P <0.01).

In a second model that adjusted for age, race, albumin, beta-blockers, aspirin, coronary artery disease, stroke, diabetes, smoking, radiation and athracyclines, tachycardia was associated with overall mortality with a risk ratio of 2.8 (p <0.001).

Future plans

The researchers plan to conduct an analysis to compare the results of patients with tachycardia who received beta-blockers and those who did not receive it, although Okwuosa pointed out that the number of patients in these groups is relatively small.

She said: "We only have a couple of patients, about 50, all with cancer, so it would be useful as part of a larger study to see if we were using beta-blockers, which would have a positive impact on patient mortality. " which are tachycardic. "

Okwuosa added: "It's something that's in preparation, something we're analyzing and that we think we're getting funding to study prospectively as part of a study." randomized controlled trial. "

Tomaselli agreed that if tachycardia "reflected minor but existing heart muscle weakness", for example, because of cancer treatment, "beta-blocker therapy may actually improve outcomes".

He added: "This cohort is complicated by the fact that it has had a primary malignancy and a primary tumor that may be the most important factor in overall mortality and outcome at the end of the day, but if heart, I think beta blockers are probably a good treatment option. "

No funding for the study has been reported. The investigators did not reveal any relevant financial relationship.

Advancing Cardiovascular Care for the Cancer Patient: Summary 21. Presented on January 25, 2019.

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