A study published in Europace has found that pregnant women with an implantable cardioverter defibrillator (ICD) can have a good outcome but medical and device complications can occur.
Pia Schuler, The Grown Up Congenital Heart Disease Unit, The Heart Hospital, University College London Hospitals, London, UK, and others reported that there is little data for the effect of pregnancy on women with ICDs. Thus, they reviewed the outcome of pregnant women with an ICD at their centre.
Schuler et al identified 19 pregnancies in 14 women with an ICD between September 2001 and October 2010. The mean age at conception was 33 and the mean time between receiving an ICD and first pregnancy was 3.8 years. Nine patients had an ICD for primary prevention (eg, non-sustained ventricular tachycardia) with the remaining five patients having an ICD for secondary prevention (eg, sustained ventricular tachycardia). Of the 19 pregnancies, 18 continued beyond 24 weeks and resulted in live births (one pregnancy was terminated due to severe foetal chromosomal abnormality).
There were no deaths, but two patients developed heart failure and one woman with hypertrophic cardiomyopathy had a major thromboembolic complication. After a 13x15mm thrombus (attached to a ventricular lead near the tricuspid valve) was picked via routine echocardiography during the second trimester, the woman received treatment with dalteparin. She remained well throughout her pregnancy and the thrombus did not change in size but one week after undergoing an elective caesarean at 36 weeks, she presented with leg swelling and breathlessness. Schuler et al noted: “Transthoracic echocardiography confirmed an increase in thrombus size at 41mmx18mm with obstruction to tricuspid valve inflow. She underwent urgent surgical removal of the thrombus and ICD system (generator and leds) via sternotomy and made an uneventual recovery.”
Schuler et al also reported that arrhythmia episodes were not “uncommon” particularly given that most of the patients in the study had received their ICD for primary prevention purposes, but they added: “All life-threatening arrhythmias were appropriately detected and/or treated by the device and there were no inappropriate device therapies.”
The authors claim that as many women, of child-bearing age, with an ICD seem willing to accept the risk of pregnancy, despite the lack of data, “there are likely to be an increasing number of such patients.” They added: “Our single centre experience demonstrates that pregnancy outcome overall is generally good but medical and/or device complications are frequent, occurring in eight of the 19 pregnancies.”
Schuler told Cardiac Rhythm News: “From our study we have shown that women with an ICD implant generally do well in pregnancy but they are clearly a high risk group, at risk of medical and lead complications. Women with an ICD who therefore wish to contemplate pregnancy should receive expert pre-pregnancy counselling so they are informed of any potential complications, including thromboembolic risk, which is based on an individualised risk assessment. It is also during this review that any changes to drug therapy can be made if needed. With underlying cardiac disease and an ICD in situ, these women require co-ordinated multidisciplinary pregnancy care and therefore need to be managed in a specialist centre where input is available at all times. In order to ensure a good outcome for both mother and foetus, arrhythmias need to be aggressively suppressed and euvolaemia maintained, while always remembering that maternal health is the priority.”