Search

There are several techniques for performing coronary atherosclerotic plaque modification, known as atherectomy . Historically, clinical trials show mostly equivalence between various coronary atherectomy techniques, balloon angioplasty, and percutaneous coronary stenting. In the last several years the use of a given atherectomy technique has been mostly as a means of facilitating stent delivery in vessels that are heavily calcified. No clinical trials have shown superiority of any atherectomy method over more standard techniques of percutaneous coronary intervention. This review begins with a discussion of directional atherectomy, which is no longer available. The rotational atherectomy technique and its clinical trial data are presented. Orbital atherectomy is then discussed in detail, including the relevant clinical trials. Finally, laser atherectomy techniques are reviewed, and the pertinent trial data are presented. Lastly, future directions are detailed.

Over the past decade, percutaneous renal denervation has been vigorously investigated as a treatment for resistant hypertension. The SYMPLICITY radiofrequency catheter system (Medtronic CardioVascular Inc., Santa Rosa, CA, USA) is the most tested device in clinical trials. After the positive results of small phase I and II clinical trials, SYMPLICITY HTN-3 (a phase III, multi-center, blinded, sham-controlled randomized clinical trial) was completed in 2014, but did not show significant blood pressure lowering effect with renal denervation compared to medical therapy and caused the investigators and industry to revisit both the basic science elements of renal denervation as well as the design of related clinical trials. This review summarizes the SYMPLICITY trials, analyzes the SYMPLICITY HTN-3 data, and provides insights gained from this trial in the design of the most recent clinical trial, the SPYRAL HTN Global clinical trial. Other than hypertension, the role of renal denervation in the management of other disease processes such as systolic and diastolic heart failure, metabolic syndrome, arrhythmia, and obstructive sleep apnea with the common pathophysiologic pathway of sympathetic overactivity is also discussed.

Coronary artery chronic total occlusion (CTO) is defined as an occluded coronary artery segment without anterograde flow for at least three months. It can be classified as a “true” or “functional” CTO based on flow characteristics. In “true” CTO, there is no anterograde flow. In “functional” CTO, there is minimal anterograde flow through the occluded segment of the coronary artery. CTO is a common finding during coronary angiography and its prevalence may vary depending on the reported literature. Among patients without previous coronary artery bypass grafting (CABG), CTO is found in about 20–30% of the patients. CTO may develop insidiously over a period of time and involve a complex interplay between intracellular and extracellular factors, smooth muscle and foam cells, calcification, and neovascularization. There is a growing body of evidence to support that CTO revascularization may improve clinical outcome when compared to medical management. Both the European and American cardiovascular societies support CTO revascularization with a class 2a recommendation (level of evidence B). Historically, due to low procedural success rate, apparent inefficient resource utilization, potential increase in complication rates and uncertain clinical benefits, only about 10–20% of patients with CTO are treated with percutaneous coronary intervention (PCI). Recent advances using novel and innovative techniques with dedicated equipment have significantly improved the procedural success rate for CTO PCI to about 90% in the hands of experienced operators. With increasing interest in CTO PCI coupled with increased educational effort, CTO PCI likely will become more accessible to patients in need of CTO revascularization. Ongoing advancement in innovative techniques and equipment will continue to improve procedural success rates and reduce procedural complication rate for CTO PCI. Furthermore, there are a number of prospective clinical trials on the horizon which should help define the clinical benefits and limitations of CTO PCI in the near future.