The revised percutaneous coronary intervention guidelines contain several notable changes from the prior, 2005 version. Here are some important updates or additions highlighted by Dr. James C. Blankenship:
• The post PCI aspirin dose now stands at 81 mg per day, a change from multiple prior dose options, to make aspirin treatment "clearer and simpler."
• For patients undergoing PCI for acute coronary syndrome, the guidelines committee added prasugrel (Effient) and ticagrelor (Brilinta) to the previously listed clopidogrel (Plavix) as antiplatelet drug options that continue for at least 12 months post PCI. But the new guidelines leave it to individual physicians to decide which of these P2Y12-receptor binders to prescribe.
• On the subject of post-PCI anti-platelet treatment, the guidelines also discourage routine genetic or functional testing to identify patients with impaired clopidogrel metabolism, instead recommending that physicians target these tests to "high-risk" patients. High-risk patients are those with a drug-eluting stent in a coronary artery where development of a thrombus would be life threatening, such as in an unprotected left main or the last remaining patent coronary artery, Dr. Blankenship said.
• An important anti-platelet change of note in the CABG guidelines is that the window for discontinuing P2Y12-receptor binders before cardiac surgery was cut from 5-7 days to 24 hours. "There is a reluctance against doing surgery in the presence of these drugs that is to the disadvantage of patients," said Dr. Peter K. Smith, vice-chairman of the CABG guidelines committee. Stopping these drugs several days before surgery in a stable, elective patient is okay. For unstable patients who are in a prothrombotic state and are undergoing urgent surgery, these drugs should not be stopped until 24 hours before surgery, Dr. Smith noted. The CABG guidelines also say that aspirin, at a dosage of 100-325 mg per day, should be administered preoperatively to CABG patients, meaning aspirin should be continued right up to the time of surgery, he added.
• The guidelines leave it to the operator’s discretion to use femoral or radial artery access, saying that "radial artery access can be useful to decrease access site complications." Radial-artery access "may be a class 1 recommendation in the future, but we didn’t feel we could justify class 1 at this time," Dr. Blankenship said.
• The guideline set a door-to-device time for primary PCI of 120 minutes, up from 90 minutes in the prior version. Setting 120 minutes as a "system goal recognized the reality" that in some settings involving patient transfer a 90-minute goal was unrealistic, and that "PCI within 120 minutes is good," he said.
• The PCI guidelines also say that cardiac catheterization laboratories should routinely record the procedural radiation dose delivered to a patient, and should define thresholds of exposure and have follow-up protocols in place for patients who receive high radiation doses. This new addition to the guidelines reflects "increasing concern about radiation exposure to patients," Dr. Blankenship said. No data now exist on appropriate exposure thresholds and what constitutes optimal follow-up, but medicine in general is becoming more focused on the need to track each person’s lifetime radiation exposure from all medical sources, he said.
Dr. Blankenship said that he has received research support from Abiomed, AstraZeneca, Boston Scientific, Conor Medsystems, Kai Pharmaceuticals, and Schering-Plough. Dr. Smith said that he has been a consultant to Eli Lilly and Baxter Biosurgery.
[Read more: New PCI, CABG Guidelines Embrace the Heart Team.]