| Background:Patent ductus arteriosus (PDA) is one of the most common congenital heart diseases. The hemodynamic impact of the large PDA is that left-to-right shunt on the pulmonary level leads to a significant increase in left ventricular preload, thereby significantly increasing the left ventricle size, resulting in left ventricular remodeling and heart failure. Currently, device closure has become the first-choise in patients with PDA. However, people pay little attention to the changes of left ventricular function and remodeling after percutaneous closure of PDA, as well as risk factors for postoperative recovery of left ventricle (LV), resulting poor recovery in cardiac remodeling and heart function after percutaneous closure of PDA.Objective:This study aims to investigate the changes of LV size and function after transcatheter closure of PDA in patients with enlarged LV before procedure, as well as the risk factors for LV size and function recovery, so as to provide evidence for improving cardiac function in these patients after PDA closure.Methods:All patients with isolated PDA and enlarged LV who underwent transcatheter device closure between January 2004 and December 2012 at the Department of Congenital Heart Disease, General Hospital of Shenyang Military Region were enrolled. Inclusion criteria were ①isolated PDA；②age≥12 years; ③left ventricular end-diastolic diameter (LVEDD) greater than normal (ie,44mm in adolescent,55mm in adult male,50mm in adult female);and ④left ventricular election fraction (LVEF)>0.5 before procedure. The patients with normal LV the next day after procedure were followed up for 6 months and those with enlarged LV were followed up till the LV volume was restored to normal size. A comprehensive echocardiographic examination including LVEDD, left ventricular end systolic diameter (LVESD), left atrial diameter (LAD), right ventricular diameter (RVD), left ventricular ejection fraction (LVEF), fractional shortening (FS), left ventricular end diastolic volume index (LVEDVI) and left ventricular end-systolic volume index (LVESVI) were performed at every follow-up visit.Results:A total of 391 cases of PDA patients (63 males) aged 35±16 (range; 12-75) years were encluded into this study. The diameter of PDA at the pulmonary artery end was 7±2 mm.11 paitents underwent PDA closure with muscular ventricular septal occluders and 380 with PDA occluders. The size of the devices was 21±5 mm and 14±4 mm, respectively. UCG showed complete closure of the PDA at the next day after procedure in all the patients.X-ray examination showed decreased cardio-thoracic ratio (CTR) 24 hours after procedure (P<0.05). Except for left ventricular wall thickness (LVT), UCG showed a significant decrease in RVD, LAD, LVEDD, LVEDVI, LVESVI, LVEF and FS compared to the baseline values (P<0.05). However, a normal size LV was only observed in 140 (35.8%) patients the next day after procedure and an enlarged LV was still present in 35 (9.86%) patients even 12 months after procedure.In the patients with a normal size LV the next day after procedure, a sharp decrease in LV size was accompanied with a significant decrease of LVEF (P<0.05), which was up to the baseline value until 6 months after procedure. In the patients with an enlarged LV 12 months after procedure, though decreased significantly by the interruption of the shunt (P<0.05) 24 hours after peocedure, the LV size changed slowly thereafter. Similar to the patients with a normal size LV the next day after procedure, LVEF was significantly decreased after PDA closure (P<0.05) and was restored to baseline values until 6 months after procedure.F test showed that the age, the PDA size and the baseline pulmonary artery pressure and LV volumes in patients with a normal size LV within 6 months after procedure were significantly different from those values in patients with an enlarged LV 6 months after procedure. Cluster analysis divided the patients into two clusters:one with a normal size LV within 6 months after procedure and the other with an enlarged LV 6 months after procedure.Althouth there were significant differences in gender, age, PDA size, pulmonary artery pressure, LVD, LVEF and the severity of mitral incompetence (MI) and aortic incompetence (AI) between the patients with a normal size LV within 6 months after procedure and those with an enlarged LV 6 months after procedure, stepwise discriminant analysis showed that only gender, age, the baseline mean pulmonary arterial pressure (mPAP) and the baseline LVESVI were the independent risk factors for LV size recovery after procedure. Male, advanced aged, elevated mPAP and enlarged LVESVI mean more difficult to recover.Conclusion:In the patients with PDA and enlarged LV size, device closure of PDA not only causes a significant decreae in LV size but also leads to marked deterioration of LV function. It takes about half a year for LVEF to restore to baseline level after PDA closure. Interruption of the left-to-right shunt does not mean the immediate normalization of the LV. In some patients, it takes one to several years for LV to restore to normal size after procedure. The gender, age, and the baseline mPAP and LVESVI are the independent risk factors for LV size recovery after PDA closure. This finding suggests that it is important to administer afterload-reducing drugs in the patients with enlarged LV after PDA closure. |
PDF Full Text Request