Recent data support preventive multivessel PCI in STEMI patients

SNOWMASS, COLO. – ST-elevation MI guidelines released just last year by the American College of Cardiology/American Heart Association are already in need of revision in light of important new evidence about the benefits of complete rather than culprit vessel–only revascularization at the time of primary percutaneous coronary intervention.

"The guidelines need a facelift," Dr. David R. Holmes Jr. said at the Annual Cardiovascular Conference at Snowmass.

Dr. David R. Holmes, Jr.

The 2013 ACC/AHA guidelines deem PCI of a noninfarct artery at the time of primary PCI in STEMI patients without hemodynamic compromise to be harmful. This practice is categorized as class IIIB, meaning "don’t do it" (J. Am. Coll. Cardiol. 2013;e78-140). Similarly, the 2012 European Society of Cardiology STEMI guidelines state, "Primary PCI should be limited to the culprit vessel with the exception of cardiogenic shock and persistent ischemia after PCI of the supposed culprit lesion" (Eur. Heart J. 2012;33:2569-619).

But the recently published PRAMI (Preventive Angioplasty in Myocardial Infarction) trial is a game changer in this regard. Investigators at five U.K. centers randomized 465 acute STEMI patients to infarct artery–only primary PCI or to preventive primary PCI of both the culprit vessel and noninfarct coronary arteries with major stenoses.

"I like the concept of prevention through intervention. It makes sense, I think," commented Dr. Holmes, professor of cardiovascular medicine at the Mayo Clinic in Rochester, Minn.

The tricky part will be to craft the revised guideline recommendations so as to encourage preventive PCI while avoiding the all-too-human temptation to overestimate lesion severity and engage the well-known oculostenotic reflex, he added.

During a mean follow-up of 23 months in the PRAMI study, the primary outcome – a composite of cardiac death, nonfatal myocardial infarction (MI), or refractory angina – occurred in 21 patients assigned to preventive PCI, compared with 53 randomized to infarct artery–only PCI, for a highly significant 65% relative risk reduction (N. Engl. J. Med. 2013;369:1115-23).

"Do the STEMI guidelines need a facelift?" Dr. Holmes asked the next speaker at the conference, who just happened to be ACC President-elect Patrick T. O’Gara, M.D., chair of the ACC/AHA STEMI Guideline Writing Committee.

"I think, actually, there are several areas in the STEMI guidelines that require revision within the year of their publication," responded Dr. O’Gara, professor of medicine at Harvard Medical School and director of clinical cardiology at Brigham and Women’s Hospital, Boston.

"I think this preventive PCI concept is one – and we need to get good minds together to hit the right mark. Another is routine use of thrombus aspiration at the time of primary PCI. A third area might be the logistics around hypothermia in out-of-hospital cardiac arrest survivors: Are we trying to achieve a certain temperature or achieve some other outcome? We anticipate that the writing committee will be re-impaneled, probably in the next 3 months, to take these on," Dr. O’Gara said.

Dr. Holmes welcomed PRAMI because it sheds new light on what has been a cloudy area of research. For example, a new Canadian meta-analysis of 26 published studies totaling 38,438 STEMI patients who underwent culprit vessel–only primary PCI and 7,886 others with multivessel primary PCI concluded there was no difference between the two strategies in terms of hospital mortality; in other words, multivessel primary PCI provided no added benefit. However, among the three randomized studies included in the meta-analysis, there was a highly significant 76% reduction in hospital mortality with multivessel primary PCI (Am. J. Heart J. 2014;167:1-14.e2). With PRAMI, that makes a total of four positive and no negative randomized trials.

In other developments pertaining to multivessel primary PCI in STEMI, Dr. Holmes noted that this intervention recently received support when applied in the setting of the STEMI patient with multivessel disease who presents with cardiogenic shock and resuscitated cardiac arrest. French investigators published a prospective observational study involving 169 such patients, 66 of whom received multivessel primary PCI while the other 109 underwent culprit vessel–only primary PCI. The primary endpoint, a 6-month composite of recurrent cardiac arrest and death due to cardiogenic shock, occurred in 50% of those who got multivessel PCI, compared with 68% of those with culprit vessel-only PCI (JACC Cardiovasc. Interv. 2013;6:115-25).

"The conclusion is, if somebody comes in with STEMI and cardiogenic shock and they’ve arrested, you should treat everything you can. Go for it." Dr. Holmes said.

A couple of noteworthy recent studies looked at the effect of chronic total occlusion (CTO) in a non–infarct-related artery in STEMI patients. Dutch investigators reported on 5,018 consecutive unselected STEMI patients. Twelve percent had cardiogenic shock, 64% had single-vessel disease, 23% had multivessel disease with CTO in a non–infarct-related artery, and 13% had multivessel disease without a CTO. Thirty-day mortality was 11% in STEMI patients with multivessel disease and a CTO, 4.3% in those with multivessel disease without a CTO in a non–infarct-related artery, and 3% in those with single-vessel disease. In the group with cardiogenic shock, 30-day mortality was 61% in patients with a CTO, 42% in those with multivessel disease but no CTO, and 26% with single-vessel disease (Eur. J. Heart Fail. 2013;15:425-32).