Utility of Follow-Up Echocardiograms in Uncomplicated PDA Device Closures Performed During Infancy

Percutaneous PDA closure is progressively becoming more common [10, 15]. Immediate complications are well known, but longer-term results are less well delineated, especially in infants. Because of the lack of long-term data, current guidelines state that it is appropriate to obtain TTEs on a regular basis, even in patients with no or mild sequelae [20]. In this study, infants that underwent an uncomplicated PDA device closure had no long-term complications related to the PDA device. Follow-up surveillance TTEs for these infants did not change clinical management for these patients.

Reported complications after PDA device closure include venous/arterial vascular damage, tricuspid valve damage, device embolization, left pulmonary artery stenosis, and descending aorta stenosis [10, 13, 15, 19]. Most of these complications can be appreciated during the device procedure or relatively soon after the device procedure [10, 19]. Of these complications, left pulmonary artery and descending aorta stenosis are the complications that may be noted weeks to months after device placement [11, 12, 15, 22]. Previous studies in infants have noted increased velocities in the LPA and DAo immediately after PDA device placement that generally remained stable or improved over time [9, 11, 16]. Actual catheterization or surgical interventions to relieve LPA or DAo stenosis in infants is relatively rare with the incidence ranging from 0 to 4% [11‐13, 16]. Most of these interventions also appeared to occur within the first few months after PDA device placement [11, 12, 15].

This study, using a cohort of infants undergoing percutaneous PDA closure without procedural complications, confirms the aforementioned published findings of improved ventricular function, normalization of left ventricular dimensions, and stable to decreasing velocities in the LPA and DAo with no need for catheter or surgical intervention in these vessels [11, 15, 22]. This study benefits from a longer follow-up compared to the previous studies in infants with a mean follow-up of 56.5 months and with the longest follow-up noted to be 14.5 years after device placement. Prior studies mean follow-up periods ranged from approximately 1 to 3 years with most studies evaluating only the first few months after device placement [11, 15, 16, 19].

The earlier studies studying PDA device closure evaluated all infants that underwent closure whereas this study only evaluated a selected group of infants that had no concerns after PDA device placement after a 3-month time period. This may explain the lower incidence of complications reported in this study. This cohort was specifically chosen because of the recent guidelines that state that TTEs are generally appropriate for surveillance for the patient’s lifetime even in an asymptomatic patient with no or mild sequalae [20]. This study noted that there were no cardiac complications seen if there were no concerns on the first TTE at least 3 months post device placement. The long-term complications of worsening LPA or DAo stenosis did not occur in this infant cohort. The explanation may be that if there was no significant stenosis noted immediately post device placement, there would be no nidus for fibrosis and narrowing of the respective vessels, and somatic growth would prevent any subsequent stenosis [11, 16, 22]. These findings are consistent with a study among 315 patients in which most complications were found within 3 months post PDA device closure. That study concluded that “extended regular monitoring via echocardiography is not indicated after percutaneous PDA occlusion, and patients can be discharged safely from follow-up once there is no residual shunt or obstruction to the adjoining vessels” [21]. The average age and weight at PDA procedure in that study was approximately 3 years and 14.0 kg with the longest follow-up at 11 years post device placement in that study. Our study’s population was significantly younger (141 days) and weighed less (4.2 kg) with the longest follow-up at 14.5 years post device placement. This suggests that even in a high risk population of predominantly premature infants, the long-term results are similar to an older cohort of patients.

Taken together, the findings from these two studies challenge current recommendations and point to the need to further investigate the usefulness and cost-effectiveness of lifelong TTEs in an uncomplicated patient cohort post PDA device placement. Recommendations for lifelong TTE surveillance for this uncomplicated infant cohort may be modified from an “appropriate” rating of 7–9, to “may be appropriate” with a rating of 4–6. These guidelines do take into account if clinical status and/or new concerning signs or symptoms arise that a TTE is appropriate with a rating of 9 [20]. Assuming a normal lifespan of approximately 80 years, this could theoretically decrease TTEs in this population by 16 TTEs per person. Limiting the use of TTEs in this low risk group would substantially decrease their lifetime healthcare cost and may enable better use of resources in favor of more ill patients. As seen in this study, there was a significant amount of TTEs at least 1 year post device placement that did not change clinical management.

Though this study had the longest follow-up to date post PDA device placement with TTEs in an uncomplicated cohort of patients, it is always possible that even longer follow-up with routine TTEs would have uncovered late complications from the device placement. This single-center study cannot definitively say that late complications are never occurring. Only larger studies with longer follow-up can better define the utility of follow-up TTEs in asymptomatic patients with no concerns on follow-up TTE.

There were multiple limitations to this study. This was a single-center retrospective chart review study with all the inherent limitations of such a design. Furthermore, only a relatively small, selected population was evaluated. This study evaluated patients over an 18-year time span, so variances in individual and institutional management of PDA follow-up occurred and were not taken into account for analysis. There was no set echocardiographic timing schedule for these patients with the schedule determined by the primary cardiologist, so a more uniform analysis of TTE changes could not be performed. There were no long-term complications documented, so risk factors could not be determined. Approximately a quarter of patients were lost to follow-up so it is possible that late complications may have been missed. However, we think that this is unlikely since these patients would have probably been referred back to our institution if clinical concerns had arisen.