ESC Congress 2012 Offers Slate of Guidelines, New MI Definition

MUNICH, Germany—This year’s European Society of Cardiology (ESC) Congress is replete with updated guidance for clinical practice in a number of areas relevant to interventional cardiology that span ST-segment elevation myocardial infarction (STEMI), valvular disease, heart failure, and atrial fibrillation (A-fib). Along with a newly revised universal definition of myocardial infarction (MI), all were presented in an information-packed session on Sunday, August 26, 2012, and published online ahead of print in the European Heart Journal.

Rethinking What Makes for an MI

Kristian Thygesen, MD, of Aarhus University Hospital (Aarhus, Denmark), and Joseph S. Alpert, MD, of the University of Arizona College of Medicine (Tucson, Arizona), both shared details on the newest universal definition of MI developed jointly by the ESC, the American College of Cardiology, the American Heart Association, and the World Heart Federation

Much has stayed the same since the 2007 definition, Dr. Thygesen noted, including the main components of MI, myocardial ischemia and necrosis. As biomarker detection has evolved in recent years, the 2012 definition specifies the levels of troponin required to diagnose procedure-related MI.

In particular, MI in conjunction with PCI is defined by cardiac troponin elevation greater than 5 times the 99^th percentile upper reference limits in patients with normal baseline values, or as a rise in cardiac troponin levels greater than 20% if baseline values were elevated and are stable or falling. In addition, diagnosis requires either symptoms suggestive of myocardial ischemia, new ischemic ECG changes or angiographic findings consistent with a procedural complication, or imaging demonstration of new loss of viable myocardium or new regional wall motion abnormality.

According to the ESC document, being released online ahead of print in the European Heart Journal and 4 other academic journals, “the conceptual meaning of ‘myocardial infarction’ has not changed, although new sensitive diagnostic methods have been developed to diagnose this entity. Thus, the diagnosis of acute MI is a clinical diagnosis based on patient symptoms, ECG changes, and highly sensitive biochemical markers, as well as information gleaned from various imaging techniques. It is important to characterize the type of MI as well as the extent of the infarct, residual LV function, and the severity of CAD and other risk factors, rather than merely making a diagnosis of MI.”

“We keep tightening up the definition, trying to eliminate patients who are not having myocardial necrosis secondary to ischemia. This is an area of considerable consternation and confusion for many clinicians,” Dr. Alpert said, noting that there may be other causes of myocardial injury at work.

“We want everyone to use this definition,” he concluded. “[We] are looking forward to the day when a patient in Tokyo has a myocardial infarct and it will be defined the same way as a patient in Copenhagen, Paris, Tel Aviv, or Tucson, Arizona.”

Focusing on STEMI

Philippe Gabriel Steg, MD, of Hôpital Bichat-Claude Bernard (Paris, France), and Stefan James, MD, PhD, of Uppsala University Hospital (Uppsala, Sweden), presented new 2012 ESC guidelines for STEMI that stress the importance of timely treatment.

On a system-wide level, prehospital management of STEMI patients must rely on regional networks that expand access to primary PCI, the guidelines suggest. Ambulance teams should be able to identify STEMI in the field and administer initial therapy, including thrombolysis, when needed. PCI centers, meanwhile, must be able to initiate PCI within 60 minutes from the initial call on a round-the-clock basis.

Several targets were set for time from first medical contact to:

• ECG and diagnosis: ≤ 10 minutes
• Primary PCI: ≤ 90 minutes (cutoff is 60 minutes if patient presents at a PCI center or within 2 hours of onset, or has large area at risk).
• Fibrinolysis: ≤ 30 minutes (acceptable if PCI cannot be performed ≤ 120 minutes)

The recommendations also touch on dual antiplatelet therapy (DAPT), specifying that aspirin and an ADP-receptor blocker (clopidogrel, prasugrel, or ticagrelor) continue for 12 months in primary PCI patients. The minimum duration should be 1 month after BMS and 6 months after DES. “If the patient has no contraindications to prolonged DAPT (indication for oral anticoagulation, or estimated high long-term bleeding risk) and is likely to be compliant, DES should be preferred over BMS,” Dr. Steg said, noting that “radial access should be preferred over femoral access, if performed by an experienced radial operator.”

By placing clopidogrel on the same footing as other antiplatelet drugs, the medication “clearly . . . has been downgraded,” he added. “The novel agents are [now even] preferred.”

Percutaneous Valve Treatment Gains Traction

New guidelines on valvular disease, released jointly by the ESC and European Association for Cardiothoracic Surgery, were shared by Alec Vahanian, MD, of Hôpital Bichat (Paris, France), and Ottavio Alfieri, MD, of San Raffaele University Hospital (Milan, Italy).

In patients with aortic valve disease, the guidelines advise, TAVR should only be done at hospitals with a multidisciplinary heart team and on-site surgical backup. The noninvasive therapy received a class I B recommendation in patients with severe symptomatic aortic stenosis who are judged by a heart team to be unsuitable for surgical replacement and are likely to gain improvement in quality of life and have a life expectancy of more than 1 year. TAVR was classified as class IIa B for patients who may still be suitable for surgery but are thought by the heart team to be better candidates for TAVR based on their risk profile and anatomic suitability.

For mitral regurgitation, the guidelines position surgical repair as the preferred approach due to its durability. But percutaneous repair was described as safe and generally well tolerated. Though less effective at reducing mitral regurgitation, the percutaneous approach may be considered for symptom relief in high-risk or inoperable patients who do not respond to medical therapy and have a life span greater than 1 year (class IIb C).

Advice Also Given for Heart Failure and A-Fib

Other recommendations released at ESC Congress 2012 addressed the management of heart failure and A-fib.

John McMurray, MD, of the University of Glasgow (Glasgow, Scotland), shared new guidelines for heart failure that look favorably on left ventricular assist devices and give a new indication for cardiac resynchronization therapy (CRT) in patients with mild symptoms. CRT is considered most beneficial in patients with left bundle branch block and those who are in sinus rhythm. In patients with heart failure due to aortic stenosis and who are “not medically fit for surgery (eg, because of severe pulmonary disease),” the document states, TAVR “should be considered.”

A focused update to the 2010 ESC guidelines for A-fib was presented by John Camm, MD, of St. George’s, University of London (London, United Kingdom). Notably, the CHA₂DS₂-VASc score has replaced the CHADS₂ score for determining stroke risk. Novel oral anticoagulants, meanwhile, are now preferred to vitamin K antagonists in most A-fib patients, though there was no decision on how to choose the best drug.

In addition, percutaneous closure of the left atrial appendage gained recognition. “Interventional, percutaneous LAA closure may be considered in patients with a high stroke risk and contraindications for long-term oral anticoagulation,” the update states, giving the treatment a class IIb B recommendation.

Sources:

1. Perk J. 2012 ESC guidelines overview: Cardiovascular disease prevention in clinical practice. Presented at: ESC Congress. August 26, 2012. Munich, Germany.
2. McMurray J. ESC guidelines overview: Acute and chronic heart failure. Presented at: ESC Congress. August 26, 2012. Munich, Germany.
3. Steg PG, James SK. ESC guidelines overview: Acute myocardial infarction in patients presenting with ST-segment elevation. Presented at: ESC Congress. August 26, 2012. Munich, Germany.
4. Thygesen K, Alpert JS. ESC guidelines overview: Third universal definition of myocardial infarction. Presented at: ESC Congress. August 26, 2012. Munich, Germany.
5. Vahanian A, Alfieri O. ESC guidelines overview: Valvular heart disease. Presented at: ESC Congress. August 26, 2012. Munich, Germany.
6. Camm J. ESC guidelines overview: Atrial fibrillation focused update. Presented at: ESC Congress. August 26, 2012. Munich, Germany.

Disclosures:

Statements regarding conflicts of interest can be found online at http://www.escardio.org/guidelines.

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