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Background Current guidelines suggest the use of atrial synchronous mode (VDD) pacemakers in patients with atrioventricular (AV) block and normal sinus node function. However VDD mode is being used much less than expected. The objectives of our study were to evaluate the efficacy of VDD pacing in long-term follow-up and to find risk factors for VDD loss. Methods We retrospectively evaluated all patients with VDD pacemakers who were implanted in our center between 1995 and 2007. Results During the study period, 123 consecutive patients with AV block (51% men, age 62 ± 17.8 years) received a VDD pacemaker. Mean follow up duration was 4.5 ± 3.2 years. At the last follow up visit, 21 patients (21.6%) lost their original VDD mode and were programmed to ventricular-based pacing (VVIR) (undersensing, 11; chronic AF, 7; SND, 3). In 28 patients, VDD mode was restored or maintained by increasing atrial sensitivity. No episodes of atrial oversensing were observed. In multivariate analysis history of paroxysmal AF (p = 0.007, odds ratio 36.6, 95% confidence interval 2.7–493.7) and p wave lower than 1 mv during the follow up (p = 0.021, odds ratio 7, 95% confidence interval 1.3–36.7), were found risk factors to VDD loss. Conclusions VDD pacing has good long-term performance. Absence of paroxysmal AF history predicts maintenance of VDD pacing mode. Taking into account that no atrial oversensing was observed, our recommendation is to increase atrial sensitivity when P wave amplitude declines to less than 1 mv. Copyright © 2010 Wiley Periodicals, Inc.

Stents have revolutionized percutaneous coronary interventions (PCI), impacting on both acute and long-term results. However, despite improvements in stent design, stent deployment failure is not an unusual event. The aim of the present study was to assess the frequency and causes of stent deployment failure, as well as the outcome of these patients. Between 1997 and 2001, a total of 3,537 patients underwent stent-assisted PCI and delivery of 5,275 stents was attempted. In the majority of patients (118; 78.1%), stenting was performed as provisional; in the remaining 33 (21.8%) as a bailout procedure. A total of 175 (3.3%) stents in 151 (4.3%) patients failed. Failure to deliver the stent to the lesion site was the main cause in 139 patients (92%) and failure either to expand adequately the stent or premature disengagement of the stent from the balloon in only 12 patients (8%). Peripheral stent embolization occurred in 10 (0.3%) patients. Deployment of a different stent in place of the failed one was attempted in 122 patients and was successful in the majority (108; 88.5%). In-hospital major adverse cardiac events were observed in six patients (4%): three patients required emergency coronary artery bypass surgery, two had a myocardial infarction (MI), and one patient underwent urgent repeat coronary intervention. At a mean follow-up of 32.2 +/- 17.7 months, 22 major adverse cardiac event occurred in 17 patients (11.2%): 1 cardiac death, 3 patients had an MI, and 18 patients required target vessel revascularization. One-year event-free survival for the whole group was 91.2%. Patients with stent embolization did not have any major adverse cardiac or vascular events. Thus, the rate of stent deployment failure in our series was 3.3%, mainly due to failure to deliver the stent to the site. Another stent was successfully deployed in the majority of cases and these patients had favorable short- and long-term outcomes.

Published data regarding stenting very small arteries are still limited. The BiodivYsio stent is a new stent coated with phosphorylcholine, a biocompatible molecule designed to reduce the formation of thrombus and potentially the risk of restenosis. The feasibility, safety, and efficacy of implantation of the 2.0 mm coated coronary stent were prospectively studied. We studied 97 patients from three centers who underwent elective, urgent, or bailout implantation of 106 BiodivYsio mini-stents (2.0 mm) in 101 lesions. Forty percent of lesions had unfavorable characteristics (type B2 or C) and 16% had thrombus and/or chronic total occlusion. Successful stent deployment was achieved in 100/101 lesions (99%). MLD increased from 0.49 ± 0.31 mm to 1.89 ± 0.41 mm and diameter stenosis decreased from 89% ± 7% to 5.6% ± 6%. Small vessel stenting was the only procedure in 71% patients. There was one acute stent thrombosis case. During 6-month follow-up, none died, one had MI, and one was referred to CABG due to nontarget lesion progression. Angiographic restenosis that required target lesion revascularization was performed in 8/18 that had catheterization due to chest pain or significant ischemia. Most patients improved in their clinical symptoms. The rate of major adverse cardiac events was 4.1% at 30-day and 10.3% at 6-month follow-up. This initial clinical experience indicates that the implantation of 2.0 mm stents coated with phosphorylcholine appears to be safe and efficacious in the treatment of complex coronary lesions and is associated with low target vessel revascularization rate in spite of the very small vessel diameter. Cathet Cardiovasc Intervent 2002;55:303–308. © 2002 Wiley-Liss, Inc.