Ticagrelor in Peripheral Artery Disease Endovascular Revascularization (TI-PAD): Challenges in clinical trial execution.

There is limited evidence to guide clinical decision-making for antiplatelet therapy in peripheral artery disease (PAD) in the setting of lower extremity endovascular treatment. The Ticagrelor in Peripheral Artery Disease Endovascular Revascularization Study (TI-PAD) evaluated the role of ticagrelor versus aspirin as monotherapy in the management of patients following lower extremity endovascular revascularization. The trial failed to recruit the targeted number of patients, likely due to aspects of the design including the lack of option for dual antiplatelet therapy, and inability to identify suitable patients at study sites. In response, the protocol underwent amendments, but these changes did not adequately stimulate recruitment, and thus TI-PAD was prematurely terminated. This article describes the rationale for TI-PAD and challenges in trial design, subject recruitment and trial operations to better inform the conduct of future trials in PAD revascularization. ClinicalTrials.gov Identifier: NCT02227368.

Prevention of contrast induced nephropathy: recommendations for the high risk patient undergoing cardiovascular procedures.

Contrast induced nephropathy (CIN) is the third leading cause of hospital acquired renal failure and is associated with significant morbidity and mortality. Chronic kidney disease is the primary predisposing factor for CIN. As estimated glomerular filtration rate<60 ml/1.73 m2 represents significant renal dysfunction and defines patients at high risk. Modifiable risk factors for CIN include hydration status, the type and amount of contrast, use of concomitant nephrotoxic agents and recent contrast administration. The cornerstone of CIN prevention, in both the high and low risk patients, is adequate parenteral volume repletion. In the patient at increased risk for CIN it is often appropriate to withhold potentially nephrotoxic medications, and consider the use of n-acetylcysteine. In patients at increased risk for CIN the use of low or iso-osomolar contrast agents should be utilized and strategies employed to minimize contrast volume. In these patients serum creatinine should be obtained forty-eight hours post procedure and it is often appropriate to continue withholding medications such as metformin or non steroidal anti-inflammatories until renal function returns to normal.