The prevalence of asymptomatic central sleep apnea after acute coronary syndrome is high and may be associated with the use of ticagrelor, a new study finds.
Prior studies have suggested that ticagrelor is associated with an increased likelihood of central sleep apnea. The drug’s label notes that two respiratory conditions – central sleep apnea and Cheyne-Stokes respiration – are adverse reactions that were identified after the drug’s approval in the United States in 2011. “Because these reactions are reported voluntarily from a population of an unknown size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure,” the label says.
Among 80 patients receiving ticagrelor, 24 had central sleep apnea hypopnea syndrome (CSAHS), whereas of 41 patients not taking ticagrelor, 3 had this condition (30% vs. 7.3%, P = .004), in the new study published online Jan. 20, 2021, in Sleep Medicine. A multivariable analysis included in the paper found that age and ticagrelor administration were the only two factors associated with the occurrence of CSAHS.
Findings are ‘striking’
The different rates of central sleep apnea in the study are striking, but it is not clear that asymptomatic central sleep apnea in patients taking ticagrelor is a concern, Ofer Jacobowitz, MD, PhD, associate professor of otolaryngology at Hofstra University, Hempstead, N.Y, said in an interview.
“Whether this particular drug-induced central sleep apnea is consequential” is an open question, noted Dr. Jacobowitz. “There is no evidence that shows that this is definitely harmful.”
“The different types of central sleep apnea are caused by different mechanisms and this one, we don’t know,” Dr. Jacobwitz added.
Study author continues to prescribe ticagrelor
One of the study authors, Philippe Meurin, MD, said that he continues to prescribe ticagrelor every day and that the side effect is not necessarily important.
It is possible that central sleep apnea may resolve, although further studies would need to examine central sleep apnea over time to establish the duration of the condition, he added. Nevertheless, awareness of the association could have implications for clinical practice, Dr. Meurin said.
Central sleep apnea is rare, and if doctors detect it during a sleep study, they may perform extensive tests to assess for possible neurologic diseases, for example, when the cause may be attributed to the medication, he said. In addition, if a patient who is taking ticagrelor has dyspnea, the presence of central sleep apnea may suggest that dyspnea could be related to the drug, although this possibility needs further study, he noted.
Study included patients with ACS history, but no heart failure
Dr. Meurin, of Centre de Réadaptation Cardiaque de La Brie, Les Grands Prés, Villeneuve-Saint-Denis, France, and colleagues included in their study patients between 1 week and 1 year after acute coronary syndrome who did not have heart failure or a history of sleep apnea.
After an overnight sleep study, they classified patients as normal, as having CSAHS (i.e., an apnea-hypopnea index of 15 or greater, mostly with central sleep apneas), or as having obstructive sleep apnea hypopnea syndrome (OSAHS; i.e., an apnea-hypopnea index of 15 or greater, mostly with obstructive sleep apneas).
The prospective study included 121 consecutive patients between January 2018 and March 2020. Patients had a mean age of 56.8, and 88% were men.
Switching to another P2Y12 inhibitor ‘does not seem appropriate’
“CSAHS could be promoted by the use of ticagrelor, a relatively new drug that modifies the apneic threshold,” the study authors wrote. “Regarding underlying mechanisms, the most probable explanation seems to be increased chemosensitivity to hypercapnia by a direct P2Y12 inhibitory effect on the central nervous system.”
Doctors should not overestimate the severity of the adverse reaction or consider it the same way they do OSASH, they added.
Among patients with acute coronary syndrome in the PLATO study, ticagrelor, compared with clopidogrel, “significantly reduced the rate of death from vascular causes, myocardial infarction, or stroke,” Dr. Meurin and colleagues said. “Because in this study more than 9,000 patients received ticagrelor for 12 months, CSAHS (even if it seems frequent in our study) did not seem to impair the good efficacy/tolerance balance of the drug. Therefore, in asymptomatic CSAHS patients, switching from ticagrelor to another P2Y12 inhibitor does not seem appropriate.”
A recent analysis of data from randomized, controlled trials with ticagrelor did not find excess cases of sleep apnea with the drug. But an asymptomatic adverse event such as central sleep apnea “cannot emerge from a post hoc analysis,” Dr. Meurin and colleagues said.
The analysis of randomized trial data was conducted by Marc S. Sabatine, MD, MPH, chairman of the Thrombolysis in Myocardial Infarction (TIMI) Study Group at Brigham and Women’s Hospital, and coauthors. It was published in JACC: Cardiovascular Interventions in April 2020.
They “used the gold standard for medical evidence (randomized, placebo-controlled trials) and found 158 cases of sleep apnea reported, with absolutely no difference between ticagrelor and placebo,” Dr. Sabatine said in an interview. Their analysis examined clinically overt apnea, he noted.
“It is quite clear that when looking at large numbers in placebo-controlled trials, there is no excess,” Dr. Sabatine said. “Meurin et al. are examining a different outcome: the results of a lab test in what may be entirely asymptomatic patients.”
A randomized trial could confirm the association, he said.
“The association may be real, but also may be play of chance or confounded,” said Dr. Sabatine. “To convince the medical community, the next step would be for the investigators to do a randomized trial and test whether ticagrelor increases the risk of central sleep apnea.”
Dr. Meurin and the study coauthors had no disclosures. The analysis of randomized, controlled trial data by Dr. Sabatine and colleagues was funded by AstraZeneca, which distributes ticagrelor under the trade name Brilinta. Dr. Sabatine has been a consultant for AstraZeneca and received research grants through Brigham and Women’s Hospital from AstraZeneca. He has consulted for and received grants through the hospital from other companies as well. Dr. Jacobowitz had no relevant disclosures.