Study Examines Best Time to Screen for Sleep Apnea After Heart Attack

Sleep Apnea After a Heart Attack: When Should Patients Be Tested?

Originally published October 6, 2024 | Updated October 2026

By Vincent RPSGT | Sleep Blogs

A heart attack can change many aspects of a person’s health, including breathing patterns during sleep.

Researchers have found that sleep apnea is common among patients hospitalized after a heart attack. However, an important question remains: When is the best time to test for sleep apnea—immediately after a heart attack or after the patient has recovered?

A study involving nearly 400 heart attack patients found that sleep apnea detected during hospitalization sometimes changed or disappeared during the following six months.

The findings highlight the importance of accurate diagnosis, appropriate follow-up, and individualized decisions about sleep testing and treatment.

Why Is Sleep Apnea Important After a Heart Attack?

Sleep apnea is a condition in which breathing repeatedly stops or becomes reduced during sleep.

These breathing disturbances may cause:

Repeated drops in blood oxygen levels.
Brief awakenings that interrupt normal sleep.
Increased activity of the sympathetic nervous system.
Changes in blood pressure and heart rate.
Additional stress on the cardiovascular system.

Sleep apnea is associated with several cardiovascular conditions, including high blood pressure, coronary artery disease, heart failure, and irregular heart rhythms.

However, an association does not necessarily mean that sleep apnea caused a particular patient’s heart attack.

Two Types of Sleep Apnea

Obstructive Sleep Apnea (OSA)

Obstructive sleep apnea occurs when the upper airway repeatedly narrows or closes during sleep, despite continued efforts to breathe.

Common symptoms include loud snoring, witnessed breathing pauses, gasping, and excessive daytime sleepiness.

Some patients have obstructive sleep apnea without obvious daytime symptoms.

Central Sleep Apnea (CSA)

Central sleep apnea occurs when the brain temporarily reduces or fails to send the appropriate signals to the breathing muscles.

Central sleep apnea may be associated with certain cardiac, neurological, or other medical conditions.

Distinguishing OSA from CSA is important because their evaluation and treatment can differ.

What Did the Original Heart Attack Study Find?

Research presented at the American College of Cardiology’s 66th Annual Scientific Session in 2017 investigated changes in sleep-disordered breathing after acute myocardial infarction, the medical term for a heart attack.

Researchers at the National University Heart Centre in Singapore performed overnight sleep testing in 397 patients within five days of hospitalization.

A subgroup of 102 patients underwent repeat testing approximately six months later.

The initial results showed that sleep-disordered breathing was common.

Initial testing results

52% tested positive for sleep apnea.
42% had obstructive sleep apnea.
10% had central sleep apnea.

These findings suggested that approximately half of the hospitalized patients had evidence of sleep apnea during the early recovery period.

What Happened Six Months Later?

The follow-up results were particularly interesting.

Among the patients who returned for repeat testing:

46% of those initially diagnosed with obstructive sleep apnea no longer met the study’s sleep-apnea criteria.
83% of those initially diagnosed with central sleep apnea were subsequently classified as having obstructive sleep apnea.
93% of those initially found not to have sleep apnea remained free of a sleep-apnea diagnosis.

These results suggested that the type and severity of sleep-disordered breathing may change during recovery from a heart attack.

Importantly, these percentages describe the patients who underwent follow-up testing, not all 397 participants.

The study also had limitations. The first sleep test was performed in the hospital, while follow-up testing took place at home. Differences in the testing environment and equipment may have influenced the findings.

Why Might Sleep Apnea Change After a Heart Attack?

Several factors may contribute to changes in breathing patterns during recovery.

These include changes in cardiovascular function, fluid balance, medications, sleep position, and the body’s response to acute illness.

For some patients, sleep-disordered breathing may improve as their medical condition stabilizes.

For others, obstructive sleep apnea may persist and require ongoing management.

The study did not establish exactly why individual patients’ breathing patterns changed.

What Did Later Research Show?

A related study published in 2018 in the Journal of Clinical Sleep Medicine examined sleep apnea and recovery of heart function after myocardial infarction treated with percutaneous coronary intervention.

The researchers found that measures of sleep-apnea severity and left ventricular function changed over six months.

They also observed that some patients initially diagnosed with sleep apnea no longer met diagnostic criteria during follow-up.

These findings reinforced the importance of reassessing sleep-disordered breathing in selected patients after a heart attack.

However, they do not establish that every patient should delay evaluation or treatment for six months.

What Does the American Heart Association Recommend?

A 2021 scientific statement from the American Heart Association emphasized that obstructive sleep apnea is common and frequently unrecognized among people with cardiovascular disease.

The statement identified several groups in whom screening or formal sleep assessment may be particularly appropriate, including patients with resistant hypertension, recurrent atrial fibrillation, certain forms of heart failure, and other cardiovascular conditions.

Patients with nighttime angina, myocardial infarction, or arrhythmias may also have coexisting sleep apnea.

The decision to investigate sleep apnea should be based on the patient’s medical condition, symptoms, and clinical assessment.

Should Sleep Testing Be Done Immediately or Delayed?

There is no single testing schedule that is appropriate for every patient after a heart attack.

Early evaluation may be important when a patient has:

Significant breathing disturbances during sleep.
Repeated oxygen desaturation.
Severe daytime sleepiness.
Suspected moderate or severe sleep apnea.
Certain coexisting cardiovascular conditions.
Symptoms that suggest an urgent need for assessment.

In other patients, the treating healthcare team may recommend testing after stabilization or repeating a study performed during hospitalization.

Patients should not delay sleep testing or prescribed treatment simply because an older study evaluated participants again after six months.

The cardiologist and sleep specialist should determine the appropriate timing.

What Type of Sleep Study Might Be Recommended?

Home Sleep Apnea Testing (HSAT)

Home sleep apnea testing may be appropriate for selected, medically uncomplicated adults with suspected obstructive sleep apnea.

However, patients with significant cardiovascular disease, suspected central sleep apnea, or certain other medical conditions may require more comprehensive testing.

In-Lab Polysomnography (PSG)

An attended overnight sleep study records several physiological signals, including brain activity, breathing, oxygen levels, heart rhythm, and muscle activity.

In-lab polysomnography may be particularly valuable when a healthcare provider needs to distinguish obstructive from central sleep apnea or investigate other sleep disorders.

The appropriate test depends on the patient’s medical history and clinical circumstances.

Can CPAP Help Patients With Heart Disease?

Continuous positive airway pressure, commonly called CPAP, is an established treatment for obstructive sleep apnea.

CPAP helps keep the upper airway open during sleep.

For appropriately selected patients, treatment can:

Reduce obstructive breathing events.
Improve sleep-related oxygenation.
Reduce snoring.
Improve daytime sleepiness.
Improve sleep-related quality of life.
Modestly reduce blood pressure in some patients.

However, an important distinction must be made.

Although obstructive sleep apnea is associated with cardiovascular disease, randomized clinical trials have not consistently demonstrated that CPAP prevents recurrent heart attacks, strokes, or cardiovascular death.

Patients should therefore understand CPAP as a treatment for diagnosed sleep apnea, not as a guaranteed method of preventing another heart attack.

Treatment decisions for central sleep apnea require particular care because the suitability and safety of positive airway pressure therapies depend on the patient’s underlying cardiac condition.

Never stop prescribed CPAP or other medical treatment without consulting the treating healthcare professional.

Signs of Sleep Apnea After a Heart Attack

Patients recovering from a heart attack should discuss possible sleep apnea with their healthcare team if they experience:

Loud, persistent snoring.
Breathing pauses observed by a family member.
Waking up choking or gasping.
Frequent nighttime awakenings.
Morning headaches.
Excessive daytime sleepiness.
Persistent fatigue or unrefreshing sleep.

Some people with cardiovascular disease have sleep apnea without prominent snoring or sleepiness.

For that reason, clinical assessment remains important.

New or worsening chest pain, severe breathlessness, fainting, or other symptoms suggesting a cardiac emergency require immediate emergency medical attention rather than routine sleep testing.

Five Questions to Ask Your Cardiologist

If you have recently experienced a heart attack, consider asking:

Should I be evaluated for obstructive or central sleep apnea?
Is sleep testing appropriate now, or should it be scheduled after stabilization?
Would an in-lab sleep study be more appropriate than a home sleep apnea test?
If sleep apnea is diagnosed during hospitalization, will repeat testing be necessary?
How should sleep-apnea treatment be coordinated with my cardiac rehabilitation and medications?

These questions can help patients participate in informed decisions about their recovery.

The Importance of Follow-Up

A heart attack is a major medical event, and recovery can involve changes in heart function, medication requirements, activity levels, and sleep.

Because sleep-disordered breathing may also change, some patients benefit from repeat evaluation.

The goal is not simply to identify sleep apnea once, but to determine whether it persists, how severe it is, and which treatment is appropriate.

Better Sleep. Better Heart Health.

The relationship between sleep apnea and heart disease is complex.

Research suggests that sleep-disordered breathing identified shortly after a heart attack may change during recovery.

The most important lesson is that accurate diagnosis, individualized treatment, and appropriate follow-up matter more than choosing one fixed testing date for every patient.

Patients recovering from a heart attack should work closely with their cardiologist and sleep specialist to determine the safest and most appropriate plan.

Sleep Testing & Sleep Health in Richmond, Virginia

At CanISleep, our educational resources help patients understand sleep apnea, sleep testing, and other sleep-related concerns.

If you have questions about diagnostic sleep testing, contact us to discuss available services or request an appointment.

Call: (804) 897-1705

Alternate: (804) 520-8932

Explore more articles about sleep apnea, CPAP, sleep studies, and cardiovascular health in our Sleep Health Resource Hub.

Medical disclaimer: This article is for educational purposes and does not replace professional medical advice, diagnosis, or treatment. Patients recovering from a heart attack should follow their cardiologist’s recommendations.

Research References

American Heart Association. (2025). Sleep Matters: Duration, Timing, Quality and More May Affect Cardiovascular Disease Risk. https://newsroom.heart.org/news/sleep-matters-duration-timing-quality-and-more-may-affect-cardiovascular-disease-risk

American College of Cardiology. (2017). Study Examines Best Time to Screen for Sleep Apnea After Heart Attack. https://www.acc.org/about-acc/press-releases/2017/03/08/17/03/study-examines-best-time-to-screen-for-sleep-apnea-after-heart-attack

Sleep Apnea Evolution and Left Ventricular Recovery After Percutaneous Coronary Intervention for Myocardial Infarction. Journal of Clinical Sleep Medicine (2018). https://pubmed.ncbi.nlm.nih.gov/30353816/

Yeghiazarians Y, et al. (2021). Obstructive Sleep Apnea and Cardiovascular Disease: A Scientific Statement From the American Heart Association. Circulation. https://doi.org/10.1161/CIR.0000000000000988