August 5, 2011 (Groningen, the Netherlands and Tel Aviv, Israel) — Two new studies published this week confirm clinical recommendations that a deferred angioplasty strategy of nonculprit lesions should remain the standard interventional approach in patients with ST-segment elevation MI (STEMI) undergoing primary PCI [1,2].
In the first study, an analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS AMI) study, investigators, led by Dr Ron Kornowski (Tel Aviv University, Israel), observed significantly higher one-year mortality and stent-thrombosis rates among patients undergoing multivessel PCI compared with individuals undergoing staged PCI.
In the second study, a meta-analysis that included 18 studies and more than 40 000 patients, the investigators report that multivessel PCI was associated with the highest rates of death in short- and long-term follow-up when compared with culprit-lesion PCI and staged PCI.
Dr Pieter Vlaar (University Medical Center, Groningen, the Netherlands), the lead researcher of the meta-analysis, told heartwire that the results support current guidelines discouraging multivessel primary PCI for STEMI patients. That said, the guidelines are not based on large randomized controlled clinical trials, and this had led to some confusion and variability across different centers. Even at their institution, Vlaar said clinicians differ in their opinions about whether nonculprit lesions should be treated during the initial intervention. However, these new data suggest that when significant nonculprit lesions are suitable for PCI, "they should be treated only during staged interventions."
Both studies, as well as an accompanying editorial [3], are published in the August 9, 2011 issue of the Journal of the American College of Cardiology.
HORIZONS-AMI and the Meta-Analysis
In the meta-analysis, Vlaar and colleagues included data from four prospective and 14 retrospective studies involving 40 280 patients with multivessel disease undergoing primary PCI for STEMI. Three treatment strategies were compared:
PCI of the culprit vessel only.
Multivessel PCI, defined as PCI of the culprit vessel as well as one or more nonculprit vessel lesions.
Staged PCI, defined as PCI confined to the culprit vessel only, with one or more nonculprit lesions treated in staged interventions.
Compared with the staged-PCI strategy, PCI of the culprit lesion only and multivessel PCI were associated with a significant three- and fivefold increased risk of in-hospital/30-day mortality, respectively. In addition, 30-day mortality was significantly lower in patients treated with culprit PCI compared with multivessel PCI (odds ratio 0.66; 95% CI 0.48–0.89). Regarding long-term mortality, multivessel PCI was associated with a 60% increased risk of long-term mortality compared with culprit PCI, as well as a significantly greater risk compared with staged PCI.
In the HORIZONS-AMI study, the investigators compared primary PCI of the culprit and nonculprit lesions with patients who underwent PCI of the culprit lesions only and those who underwent staged PCI of the nonculprit lesion at a later date. Of the 3602 patients enrolled in the trial, 668 underwent PCI of the culprit and nonculprit lesions for multivessel disease, of whom 275 underwent a single PCI strategy and 393 underwent staged PCI.
At one year, patients who underwent single PCI had a mortality rate of 9.2% compared with 2.3% in patients who underwent staged PCI. In addition, single PCI was associated with significantly higher rates of cardiac mortality compared with staged PCI (6.2% vs 2.0%, respectively) and higher rates of definite/probable stent thrombosis (5.7% vs 2.3%, respectively).
In their paper, Kornowski and colleagues, including senior investigator Dr Gregg Stone (Columbia University, New York), state that a "deferred angioplasty strategy of nonculprit lesions should remain the standard approach in patients with STEMI undergoing primary PCI, as multivessel PCI may be associated with a greater hazard of mortality and stent thrombosis."
Some Unanswered Questions
Commenting on the findings for heartwire , Dr David Kandzari (Piedmont Heart Institute, Atlanta, GA) said, "Both papers provide welcome information to clinicians," especially since there are few randomized trials to provide sufficient information to guide treatment decisions. Most of the clinical recommendations are based on some clinical evidence, including cohort and retrospective studies, but they are largely the opinion of interventional experts.
In the US, the American College of Cardiology/American Heart Association guidelines state definitively that PCI "should not be performed in a noninfarct artery at the time of primary PCI in patients without hemodynamic compromise." The class-III (harm)/level-of-evidence B recommendation differs slightly from the European Society of Cardiology/European Association for Cardiothoracic Surgery guidelines, which are slightly more lenient. The European guidelines state that with the exception of cardiogenic shock, PCI for STEMI should be limited to the culprit lesion (class IIa, level of evidence B).
To heartwire , Kandzari explained that treating other lesions in patients with cardiogenic shock remains a "bit of a gray area" in the US. Although the guidelines explicitly state not to perform PCI of the nonculprit lesions, some clinicians will treat other stenoses in cardiogenic-shock patients in an attempt to provide as much flow as possible. That said, there is a discrepancy between the number of clinicians performing multivessel PCI and rates of cardiogenic shock. Dr John Bittl (Ocala Heart Institute, FL), who wrote an editorial accompanying the published studies, observed a similar discrepancy. For example, in HORIZONS-AMI, 18.5% of patients underwent multivessel PCI, but only 1.5% had cardiogenic shock. In the New York State registry, 12.5% of patients were treated with multivessel PCI, but only 4.4% met the definition of hemodynamic compromise.
Kandzari said he would like to know the reasons that the clinicians performed multivessel PCI in these STEMI patients, noting that in some instances it is difficult to determine what the culprit lesion is in acute MI. Some centers might not perform left and right coronary angiography before revascularizing the patient, and without assessment of the entire coronary anatomy, it is possible, although rare, to treat the wrong lesion. Some patients might not show any improvement following culprit PCI and as a result will undergo treatment of other lesions, he said.
In his editorial, Bittl made similar statements, noting that "no single approach is applicable to the myriad presentations of STEMI." He also noted that multivessel PCI might be necessary in the cases where patients do not show improvement following primary PCI of the culprit lesion. He added that patients with severe multivessel disease might require follow-up angiography and that fractional flow reserve (FFR) can be considered during the acute phase, but the "results should be used whenever possible to support a decision for staged PCI."
To heartwire , Vlaar said the benefit of staging patients is that angiograms can be discussed with a joint heart team and additional noninvasive ischemia tests and FFR can be performed before deciding to perform additional revascularizations.
Kandzari told heartwire that there still remain some questions regarding staged PCI in STEMI patients. For example, Kandzari said the optimal time for the second PCI is unknown. In the US, revascularization is driven by reimbursement issues, with physicians not compensated for staged PCI performed within 30 days of PCI for acute MI, so most clinicians are reluctant to treat other vessels even when the patient is in the hospital.
"Financial issues aside, we still don't know if it's better to treat the nonculprit lesions when the patient is still in the hospital, two weeks after the primary PCI, or four weeks after primary PCI," said Kandzari.
In the first study, an analysis of the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS AMI) study, investigators, led by Dr Ron Kornowski (Tel Aviv University, Israel), observed significantly higher one-year mortality and stent-thrombosis rates among patients undergoing multivessel PCI compared with individuals undergoing staged PCI.
In the second study, a meta-analysis that included 18 studies and more than 40 000 patients, the investigators report that multivessel PCI was associated with the highest rates of death in short- and long-term follow-up when compared with culprit-lesion PCI and staged PCI.
Dr Pieter Vlaar (University Medical Center, Groningen, the Netherlands), the lead researcher of the meta-analysis, told heartwire that the results support current guidelines discouraging multivessel primary PCI for STEMI patients. That said, the guidelines are not based on large randomized controlled clinical trials, and this had led to some confusion and variability across different centers. Even at their institution, Vlaar said clinicians differ in their opinions about whether nonculprit lesions should be treated during the initial intervention. However, these new data suggest that when significant nonculprit lesions are suitable for PCI, "they should be treated only during staged interventions."
Both studies, as well as an accompanying editorial [3], are published in the August 9, 2011 issue of the Journal of the American College of Cardiology.
HORIZONS-AMI and the Meta-Analysis
In the meta-analysis, Vlaar and colleagues included data from four prospective and 14 retrospective studies involving 40 280 patients with multivessel disease undergoing primary PCI for STEMI. Three treatment strategies were compared:
PCI of the culprit vessel only.
Multivessel PCI, defined as PCI of the culprit vessel as well as one or more nonculprit vessel lesions.
Staged PCI, defined as PCI confined to the culprit vessel only, with one or more nonculprit lesions treated in staged interventions.
Compared with the staged-PCI strategy, PCI of the culprit lesion only and multivessel PCI were associated with a significant three- and fivefold increased risk of in-hospital/30-day mortality, respectively. In addition, 30-day mortality was significantly lower in patients treated with culprit PCI compared with multivessel PCI (odds ratio 0.66; 95% CI 0.48–0.89). Regarding long-term mortality, multivessel PCI was associated with a 60% increased risk of long-term mortality compared with culprit PCI, as well as a significantly greater risk compared with staged PCI.
In the HORIZONS-AMI study, the investigators compared primary PCI of the culprit and nonculprit lesions with patients who underwent PCI of the culprit lesions only and those who underwent staged PCI of the nonculprit lesion at a later date. Of the 3602 patients enrolled in the trial, 668 underwent PCI of the culprit and nonculprit lesions for multivessel disease, of whom 275 underwent a single PCI strategy and 393 underwent staged PCI.
At one year, patients who underwent single PCI had a mortality rate of 9.2% compared with 2.3% in patients who underwent staged PCI. In addition, single PCI was associated with significantly higher rates of cardiac mortality compared with staged PCI (6.2% vs 2.0%, respectively) and higher rates of definite/probable stent thrombosis (5.7% vs 2.3%, respectively).
In their paper, Kornowski and colleagues, including senior investigator Dr Gregg Stone (Columbia University, New York), state that a "deferred angioplasty strategy of nonculprit lesions should remain the standard approach in patients with STEMI undergoing primary PCI, as multivessel PCI may be associated with a greater hazard of mortality and stent thrombosis."
Some Unanswered Questions
Commenting on the findings for heartwire , Dr David Kandzari (Piedmont Heart Institute, Atlanta, GA) said, "Both papers provide welcome information to clinicians," especially since there are few randomized trials to provide sufficient information to guide treatment decisions. Most of the clinical recommendations are based on some clinical evidence, including cohort and retrospective studies, but they are largely the opinion of interventional experts.
In the US, the American College of Cardiology/American Heart Association guidelines state definitively that PCI "should not be performed in a noninfarct artery at the time of primary PCI in patients without hemodynamic compromise." The class-III (harm)/level-of-evidence B recommendation differs slightly from the European Society of Cardiology/European Association for Cardiothoracic Surgery guidelines, which are slightly more lenient. The European guidelines state that with the exception of cardiogenic shock, PCI for STEMI should be limited to the culprit lesion (class IIa, level of evidence B).
To heartwire , Kandzari explained that treating other lesions in patients with cardiogenic shock remains a "bit of a gray area" in the US. Although the guidelines explicitly state not to perform PCI of the nonculprit lesions, some clinicians will treat other stenoses in cardiogenic-shock patients in an attempt to provide as much flow as possible. That said, there is a discrepancy between the number of clinicians performing multivessel PCI and rates of cardiogenic shock. Dr John Bittl (Ocala Heart Institute, FL), who wrote an editorial accompanying the published studies, observed a similar discrepancy. For example, in HORIZONS-AMI, 18.5% of patients underwent multivessel PCI, but only 1.5% had cardiogenic shock. In the New York State registry, 12.5% of patients were treated with multivessel PCI, but only 4.4% met the definition of hemodynamic compromise.
Kandzari said he would like to know the reasons that the clinicians performed multivessel PCI in these STEMI patients, noting that in some instances it is difficult to determine what the culprit lesion is in acute MI. Some centers might not perform left and right coronary angiography before revascularizing the patient, and without assessment of the entire coronary anatomy, it is possible, although rare, to treat the wrong lesion. Some patients might not show any improvement following culprit PCI and as a result will undergo treatment of other lesions, he said.
In his editorial, Bittl made similar statements, noting that "no single approach is applicable to the myriad presentations of STEMI." He also noted that multivessel PCI might be necessary in the cases where patients do not show improvement following primary PCI of the culprit lesion. He added that patients with severe multivessel disease might require follow-up angiography and that fractional flow reserve (FFR) can be considered during the acute phase, but the "results should be used whenever possible to support a decision for staged PCI."
To heartwire , Vlaar said the benefit of staging patients is that angiograms can be discussed with a joint heart team and additional noninvasive ischemia tests and FFR can be performed before deciding to perform additional revascularizations.
Kandzari told heartwire that there still remain some questions regarding staged PCI in STEMI patients. For example, Kandzari said the optimal time for the second PCI is unknown. In the US, revascularization is driven by reimbursement issues, with physicians not compensated for staged PCI performed within 30 days of PCI for acute MI, so most clinicians are reluctant to treat other vessels even when the patient is in the hospital.
"Financial issues aside, we still don't know if it's better to treat the nonculprit lesions when the patient is still in the hospital, two weeks after the primary PCI, or four weeks after primary PCI," said Kandzari.
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