Role of Percutaneous Coronary Intervention in the Treatment of Cardiac Allograft Vasculopathy.

We evaluated our quarter-century experience with percutaneous coronary intervention (PCI) in patients with cardiac allograft vasculopathy (CAV). CAV is a progressive form of atherosclerosis that is characterized by diffuse intimal thickening. It is a major cause of morbidity and mortality after orthotopic heart transplantation (OHT). Effective treatment options are limited. PCI has been used as a palliative treatment in selected patients. We retrospectively analyzed 140 patients with CAV who underwent PCI from 1992 to 2017 at the University of California, Los Angeles (UCLA) Medical Center. The primary end point was freedom from death, myocardial infarction (MI), target vessel revascularization (TVR), and repeat OHT, at a follow-up of 10 years. PCI was unsuccessful in 3 patients (2%). Balloon angioplasty (n = 7), bare metal stents (n = 50), or drug-eluting stents (DES, n = 80) were used for PCI. Freedom from the primary end point was 17 ± 8%. The use of DES did not provide significant benefit for the primary end point (23 ± 14% vs 10 ± 9%, p = 0.16). Freedom from the individual end points was low: death was 43 ± 10%, MI was 74 ± 12%, TVR was 54 ± 12%, and repeat OHT was 42 ± 15%. Freedom from TVR was not significantly different from DES and bare metal stent (67 ± 14% vs 52 ± 20%, p = 0.46). In conclusion, among patients who underwent PCI for CAV, freedom from the composite of death, MI, TVR, and repeat OHT was low.

Transcatheter melody valve placement in large diameter bioprostheses and conduits: What is the optimal "Landing zone"?

OBJECTIVES: This study sought to elucidate the optimal bioprosthetic valve (BPV) size prior to Melody valve implantation. BACKGROUND: BPVs provide an ideal "landing zone" for future Melody valve insertion. To guide surgical choice of BPV size, it is important to understand which BPV size can serve consistently as substrates for Melody valve placements. METHODS: A database of all patients who underwent Melody implantation at UCLA or Kaiser Permanente Los Angeles from 2010 to 2014 was analyzed retrospectively. Patients with an existing BPV were stratified into those with a valve diameter of ≥27 mm or <27 mm. RESULTS: One hundred and sixty patients underwent catheterization with the intention to implant a Melody valve. Melody valve implantation was performed in the pulmonary position in 52 patients with prior BPVs. The immediate procedural success rate was 100%. Immediately post-Melody, the right ventricular to pulmonary artery gradient was significantly higher in the <27 mm group compared to the ≥27 mm group (14.3±3 vs. 8.6±6.8, P=0.006). There was a significantly shorter time from prior valve replacement to Melody implantation in the <27 mm group. There was one patient in whom transcatheter pulmonary valve implantation was aborted due to inadequate landing zone in the <27 mm group, and no patients in the ≥27 mm group (P=NS). CONCLUSIONS: The results of this study indicate that 27 and 29 mm BPV provide a superior landing zone for Melody valve implantation with excellent immediate and intermediate term hemodynamic results when compared to smaller BPVs less than 27 mm.

Cardiovascular complications of radiotherapy.

Chest radiotherapy is routinely used to treat malignancies such as Hodgkin disease and breast cancer but is commonly associated with a variety of cardiovascular complications involving the pericardium, myocardium, valves, coronary arteries, and conduction system. Cardiovascular complications are related to the total dose of radiation and the fractionation of the dose. They are usually progressive, portend poor prognosis, and are often refractory to treatment after significant radiation exposure. The mechanism of injury is multifactorial and likely involves endothelial damage of the microvasculature and coronary arteries and liberation of multiple inflammatory and profibrotic cytokines. In conclusion, routine follow-up with a cardiologist, which might include screening for valvular disease with echocardiography and coronary artery disease with computed tomography angiography or coronary artery calcium scoring, should be considered in patients with a history of chest radiotherapy.

Cardiac allograft vasculopathy.

Cardiac allograft vasculopathy (CAV) is the most important cause of morbidity and mortality following cardiac transplantation. CAV is largely mediated by immunologic damage and infiltration of the endothelium, resulting in proliferation of vascular smooth muscle cells and subsequent luminal narrowing. There are various risk factors for the development and progression of CAV. Coronary angiography is the gold standard for the diagnosis of CAV; intravascular ultrasound also plays an important role. The management of CAV includes immunosuppression, drugs that modify conventional coronary artery disease risk factors, and percutaneous coronary intervention (PCI) or surgical revascularization for severe obstructive lesions. Although revascularization with PCI has a high immediate success rate, rates of in-stent restenosis are higher as compared with PCI of native coronary arteries, although the advent of drug-eluting stents has somewhat improved in-stent restenosis rates. Thus, the only definitive treatment of CAV is repeat transplantation. Randomized trials are needed to determine the optimal immunosuppressive and conventional risk factor-modifying agents and revascularization strategies for patients who develop CAV.

Stenting techniques for patients with bifurcation coronary artery disease.

Atherosclerotic lesions at the bifurcation of coronary arteries are associated with higher rates of restenosis following stenting, and can be technically challenging when performing percutaneous coronary intervention (PCI). Many techniques have arisen for PCI of these lesions, often incorporating the use of multiple balloons and the placement of two or more stents. A technique commonly used for bifurcations is kissing balloon angioplasty, in which two balloons are inflated simultaneously to prevent the shifting of plaque into the side branch. Provisional side branch stenting is the technique of using a stent for the main branch, and stenting the side branch only if necessary. Multiple-stent techniques include T-stenting, crush technique, culotte, simultaneous kissing stents, V-stenting, and Y-stenting; the goal of these techniques is to provide maximal apposition to the vessel wall with effective drug delivery in the case of drug-eluting stents. Additionally, dedicated bifurcation stents also exist, with apertures that allow placement of additional stents. Debulking techniques such as atherectomy can be employed as stand-alone procedures or to debulk lesions prior to bifurcation stenting. Despite these many options for PCI of bifurcation lesions, there are currently inadequate data to indicate which of these techniques is superior, and many trials have found that complex stenting techniques provide no additional benefits when compared with provisional side branch stenting. Additional, well-designed randomized trials evaluating specific stenting techniques are necessary to determine the best practice for bifurcation lesions.