Patent Ductus Arteriosus in Older Adults: Incidental Finding or Relevant Pathology?

To the Editor: A 75-year-old man presented with breathlessness, fever, and cough. Electrocardiogram (ECG) showed atrial fibrillation (AF) with fast ventricular rate. He was diagnosed with a lower respiratory tract infection and treated with antibiotics. Bisoprolol and warfarin were initiated. One month after discharge, his ventricular rate was still 150 bpm. Echocardiography showed normal left ventricular size and function, a dilated left atrium, and no significant valvular disease. A patent ductus arteriosus (PDA) was identified. N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) was 5,054 ng/L. Digoxin and eplerenone were added. Six weeks later, ventricular rate (100 bpm) and NT-pro-BNP (3,395 ng/L) dropped, and ramipril was started. Another month later, ventricular rate was 84 bpm, NT-pro-BNP was 2,605 ng/L, and the man was asymptomatic. Because it was unclear how best to manage the PDA, a systematic review was performed in PubMed using the terms patent ductus arteriosus (Title/Abstract) AND age/adult/aged/old/older/elder/elderly/woman/man/aging (Title/Abstract). Two authors independently filtered the articles obtained (Boyalla, Putzu), and a senior author (Pellicori) judged their relevance. Articles were excluded if they did not match the age inclusion criteria, lacked clinical details, were not in English, or were duplicates. Forty articles met the eligibility criteria. PDA is a congenital abnormality in which the arterial duct remains open after birth.1 After birth, the duct normally closes spontaneously within 24–48 hours in full-term infants.1 The incidence of PDA is approximately six in 10,000 live births in infants born at full term, and one in every three preterm infants.2 Forty-five individuals aged 65 and older with PDA were identified, with a female:male ratio of approximately 7:1. Breathlessness (80%) was the most common symptom. A continuous murmur was described in 54% of cases. ECGs were often abnormal, AF being common. A clinical diagnosis of PDA was suspected in only four individuals. Before echocardiography, it was difficult to diagnose PDA; some individuals had a nonspecific murmur since childhood, and others had been misdiagnosed because of the misinterpretation of murmurs. PDA was an unexpected finding in the rest of the cases. Medical therapy before the 1990s mainly consisted of diuretics and digoxin, whereas recent cases have been managed with the addition of other drugs, including angiotensin-converting enzyme inhibitors, mineralocorticoid receptor antagonists, or nitrates, particularly in very elderly adults. Until 30 years ago, surgical treatment was by ligation. More recently, surgery has become the treatment of choice for complex cases, and younger individuals are more likely to be treated percutaneously (Table S1). The hemodynamic effect of PDA in adult life depends on the size of the shunt, which depends on the flow resistance within the ductus, and the dynamic pressure gradient between the pulmonary and systemic blood flow. Impedance to blood flow appears to depend on the length, diameter, and overall configuration of the ductus in some but not all cases. PDA is a rare diagnosis in older adults that was first reported in a postmortem of a 66-year-old woman in 1897.3 Symptoms and signs of heart failure, whether or not there is a murmur, require further investigation, but small PDAs can escape detection to the echocardiographer and the cardiac surgeon.4 The European Society of Cardiology recommends PDA device closure in individuals with pulmonary hypertension or in the presence of left ventricular volume overload5 and does not take into account older adults or the presence of comorbidities. Drugs that reduce fluid and pressure overload might be effective in decreasing pulmonary pressure and natriuretic peptide levels. A previous study reported that 34% of adults (mean age 36, range 18–81) with unoperated PDA remained asymptomatic during 15 years of follow-up, suggesting that many individuals do not need any specific treatment or have symptoms that can be medically managed.6 Bacterial endocarditis is a potential complication of PDA, but its incidence has declined,7 and there is no indication for preventive PDA closure.8 The relationship between a small, incidentally discovered PDA and the individual's symptoms is difficult to judge, and no information was found on the prevalence of PDA in an unselected adult population to help guide this individual's treatment. Breathlessness is common in elderly adults and can be caused by several comorbidities, including heart failure. Diagnosing PDA in elderly adults depends on symptoms and signs and clinician awareness. This man was asymptomatic on medical therapy, and it was decided not to close the duct. Conflict of Interest: The authors declare that they have no conflict of interest. There are no financial or other relations that could lead to a conflict of interest. Author Contributions: Dierckx, Clark, Pellicori: study designed, Boyalla, Putzu: data acquisition, analysis, interpretation. All authors drafted the article and revisited it critically. All authors read and approved the final version of the manuscript. Sponsor's Role: No sponsor. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.