Dear Editor

"Time to act"1 - a message which resonates with the team on our metropolitan Delivery Suite, who this week managed an acute myocardial infarction in a postnatal lady. Our patient has two of the risk factors mentioned in the editorial, her being 36 years old and a smoker. In addition she had an important risk factor which can be missed, as demonstrated by our recent experience. Since most women with acute coronary syndrome (ACS) in pregnancy and the puerperium have no symptoms before pregnancy2, risk factor stratification is important.

Our patient, who has a history of heroin addiction and was on methadone, arrived by ambulance in preterm labour (35+ weeks gestation) and bleeding per vaginam. She had an uncomplicated vaginal delivery of a growth restricted baby soon after arrival. The total intrapartum blood loss was 540 millilitres.

One hour after delivery the patient was noted to be profoundly hypotensive with bradycardia. There was no evidence of vaginal bleeding. Physical examination was unremarkable and the hypotension responded to fluid resuscitation. An electrocardiogram (ECG) showed ST elevation on the inferior leads. A diagnosis of acute myocardial infarction was made. She was stabilised with morphine, aspirin and nitrates and was transferred for Primary Percutaneous Coronary Intervention. Angiography revealed gross spasm of the Right Coronary Artery and a 50-60% occlusion thereof. After stenting, the ECG changes normalised. She made a good recovery within 24 hours.

Urine toxicology subsequently revealed recent abuse with cocaine and other illicit substances.

Substance misuse amongst women of childbearing age is increasing3. The United States National Survey on Drug Use and Health 2005 estimates a 4% prevalence of illicit drug use in pregnant women4. Research into the effects of the various drugs of abuse on the physiology of pregnancy and on the myocardium is ongoing. Coronary spasm is a recognised adverse effect of cocaine. Accelerated atherosclerosis can be attributed in part to the smoking of tobacco and drugs.

We feel that there should be a high index of suspicion for ACS in patients with a history of substance misuse, even if they are on a supervised treatment programme. Women with a history of substance misuse are a high-risk group, and the antenatal period offers a precious opportunity to screen for cardiovascular disease and current drug use, when these women might be more likely to engage. Patients on methadone are managed as part of a multidisciplinary team, providing scope for cardiovascular risk assessment and preconception counseling as part of this process.

References

1. Nelson-Piercy C, Adamson D, Knight M. Acute coronary Syndrome in pregnancy: time to act. Heart 2012 ;98:760-761

2. Royal College of Obstetricians and Gynaecologists (RCOG). Cardiac Disease in Pregnancy (Good Practice No. 13) (2011) http://www.rcog.org.uk/files/rcog- corp/GoodPractice13CardiacDiseaseandPregnancy.pdf (accessed 29 May 2012)

3. Centre for Maternal and Child Enquiries (CMACE). Saving Mothers' Lives: Reviewing maternal deaths to make motherhood safer: 2006-2008. The eighth report of Confidential Enquiries into Maternal Deaths in the United Kingdom. BJOG 2011;118(suppl 1):1-203

4. US Dept Health Human Services, Substance Abuse and Mental Health Services Administration, Office of Applied Studies. Results from the 2005 National Survey on Drug Use and Health: National Findings. Rock-ville, Md: US Dept Health Human Services; 2006.http://www.oas.samhsa.gov/nsduh/2k5nsduh/2k5Results.pdf (accessed 31 May 2012)

Conflict of Interest:

None declared