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Intravascular Ultrasound-Guided Treatment for Angiographically Indeterminate Left Main Coronary Artery Disease: A Long-Term Follow-up Study
Distal Microcirculatory Protection During Percutaneous Coronary Intervention in Acute ST-Segment Elevation Myocardial Infarction: A Randomized Controlled Trial
these results apply to other microcirculatory protection devices such as filter-based catheters and proximal balloon occlusion and aspiration systems. The use of distal protection devices in the setting of primary PCI cannot be advocated at this point. DB
Stone GW, Webb J, Cox DA et al. for the Enhanced Myocardial Efficacy and Recovery by Aspiration of Liberated Debris (EMERALD) Investigators. JAMA 2005;293:1063–72.
Intravascular Ultrasound-Guided Treatment for Angiographically Indeterminate Left Main Coronary Artery Disease: A Long-Term Follow-up Study
Study Question: The aim of this study was to determine whether protection of the distal microcirculation from thromboembolic debris liberated during primary PCI results in improved reperfusion and decreased infarct size. Methods: The study was a prospective randomized controlled trial enrolling 501 patients aged 18 years or older with ST-segment elevation myocardial infarction (STEMI) presenting within 6 h of symptom onset and undergoing primary PCI or rescue intervention after failed thrombolysis. Patients were randomized to receive PCI with a balloon occlusion and aspiration distal microcirculatory protection system vs. angioplasty without distal protection. Coprimary end points were ST-segment resolution (STR) measured 30 min after PCI by continuous Holter monitoring and infarct size measured by technetium (Tc) 99m sestamibi imaging between days 5 and 14. Secondary end points included major adverse cardiac events. Results: Among 252 patients assigned to distal protection, aspiration was performed in 97% (242 of 251 patients), all angioplasty balloon inflations were fully protected in 79% (193 of 245 patients), and visible debris was retrieved from 73% (182 of 250 patients). Complete STR was achieved in a similar proportion reperfused with vs. without distal protection (63.3% [152 of 240 patients] vs. 61.9% [148 of 239 patients], respectively; both absolute difference, 1.4% [95% confidence interval, ⫺7.7% to 10.5%; p⫽0.78]), and left ventricular infarct size were similar in both groups (median, 12.0% [n⫽229] vs. 9.5% [n⫽208], respectively; p⫽0.15). Major adverse cardiac events at 6 months occurred with similar frequency in the distal protection and control groups (10.0% vs. 11.0%, respectively; p⫽0.66). Conclusions: The investigators concluded that distal embolic protection during primary PCI did not result in improved microvascular flow, greater reperfusion success, reduced infarct size, or enhanced event-free survival. Perspective: The study demonstrates that although embolic debris is liberated and may be retrieved in most patients by use of the balloon occlusion distal embolic protection device during primary PCI in AMI, this device does not improve microvascular flow or function, reduce infarct size, or result in enhanced event-free survival. These results may fundamentally challenge the pathophysiologic importance of distal embolization during mechanical reperfusion therapy. Further investigation is required to determine whether
Fassa AA, Wagatsuma K, Higano ST, et al. J Am Coll Cardiol 2005;45:204 –11. Study Question: The purpose of this study was to evaluate the efficacy of an intravascular ultrasound (IVUS)-guided strategy for patients with angiographically indeterminate left main coronary artery (LMCA) disease. Methods: Intravascular ultrasound was performed on 121 patients with angiographically normal LMCAs to determine the lower range of normal minimum lumen area (MLA), defined as the mean⫺2 SD. The researchers then conducted IVUS studies on 214 patients with angiographically indeterminate LMCA lesions, and deferral of revascularization was recommended when the MLA was larger than this predetermined value. Results: The lower range of normal LMCA MLA was 7.5 mm2. Of the patients with angiographically indeterminate LMCAs, 83 (38.8%) had an MLA ⬍7.5 mm2, and 131 (61.2%) an MLA ⱖ7.5 mm2. Left main coronary artery revascularization was performed in 85.5% (71 of 83) of patients with an MLA ⬍7.5 mm2 and deferred in 86.9% (114 of 131) of patients with an MLA ⱖ7.5 mm2. Longterm follow-up (mean 3.3⫾2.0 years) showed no significant difference in major adverse cardiac events (targetvessel revascularization, acute myocardial infarction, and death) between patients with an MLA ⬍7.5 mm2 who underwent revascularization and those with an MLA ⱖ7.5 mm2 deferred for revascularization (p⫽0.28). Based on outcome, the best cut-off MLA by receiver operating characteristic was 9.6 mm2. Multivariate predictors of cardiac events were age, smoking, and number of non-LMCA vessels diseased. Conclusions: The investigators concluded that IVUS is an accurate method to assess angiographically indeterminate lesions of the LMCA. Perspective: The current study shows that IVUS is a safe method to accurately assess the degree of disease in the LMCA that appears indeterminate by angiography. It also suggests that an IVUS-guided treatment strategy based on deferral of revascularization in patients with MLA ⱖ7.5 mm2 is safe. Based on available data, either IVUS or FFR appears to be a reasonable strategy to define the clinical significance of indeterminate lesions of the LMCA. DM
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these results apply to other microcirculatory protection devices such as filter-based catheters and proximal balloon occlusion and aspiration systems. The use of distal protection devices in the setting of primary PCI cannot be advocated at this point. DB
Stone GW, Webb J, Cox DA et al. for the Enhanced Myocardial Efficacy and Recovery by Aspiration of Liberated Debris (EMERALD) Investigators. JAMA 2005;293:1063–72.
Intravascular Ultrasound-Guided Treatment for Angiographically Indeterminate Left Main Coronary Artery Disease: A Long-Term Follow-up Study
Study Question: The aim of this study was to determine whether protection of the distal microcirculation from thromboembolic debris liberated during primary PCI results in improved reperfusion and decreased infarct size. Methods: The study was a prospective randomized controlled trial enrolling 501 patients aged 18 years or older with ST-segment elevation myocardial infarction (STEMI) presenting within 6 h of symptom onset and undergoing primary PCI or rescue intervention after failed thrombolysis. Patients were randomized to receive PCI with a balloon occlusion and aspiration distal microcirculatory protection system vs. angioplasty without distal protection. Coprimary end points were ST-segment resolution (STR) measured 30 min after PCI by continuous Holter monitoring and infarct size measured by technetium (Tc) 99m sestamibi imaging between days 5 and 14. Secondary end points included major adverse cardiac events. Results: Among 252 patients assigned to distal protection, aspiration was performed in 97% (242 of 251 patients), all angioplasty balloon inflations were fully protected in 79% (193 of 245 patients), and visible debris was retrieved from 73% (182 of 250 patients). Complete STR was achieved in a similar proportion reperfused with vs. without distal protection (63.3% [152 of 240 patients] vs. 61.9% [148 of 239 patients], respectively; both absolute difference, 1.4% [95% confidence interval, ⫺7.7% to 10.5%; p⫽0.78]), and left ventricular infarct size were similar in both groups (median, 12.0% [n⫽229] vs. 9.5% [n⫽208], respectively; p⫽0.15). Major adverse cardiac events at 6 months occurred with similar frequency in the distal protection and control groups (10.0% vs. 11.0%, respectively; p⫽0.66). Conclusions: The investigators concluded that distal embolic protection during primary PCI did not result in improved microvascular flow, greater reperfusion success, reduced infarct size, or enhanced event-free survival. Perspective: The study demonstrates that although embolic debris is liberated and may be retrieved in most patients by use of the balloon occlusion distal embolic protection device during primary PCI in AMI, this device does not improve microvascular flow or function, reduce infarct size, or result in enhanced event-free survival. These results may fundamentally challenge the pathophysiologic importance of distal embolization during mechanical reperfusion therapy. Further investigation is required to determine whether
Fassa AA, Wagatsuma K, Higano ST, et al. J Am Coll Cardiol 2005;45:204 –11. Study Question: The purpose of this study was to evaluate the efficacy of an intravascular ultrasound (IVUS)-guided strategy for patients with angiographically indeterminate left main coronary artery (LMCA) disease. Methods: Intravascular ultrasound was performed on 121 patients with angiographically normal LMCAs to determine the lower range of normal minimum lumen area (MLA), defined as the mean⫺2 SD. The researchers then conducted IVUS studies on 214 patients with angiographically indeterminate LMCA lesions, and deferral of revascularization was recommended when the MLA was larger than this predetermined value. Results: The lower range of normal LMCA MLA was 7.5 mm2. Of the patients with angiographically indeterminate LMCAs, 83 (38.8%) had an MLA ⬍7.5 mm2, and 131 (61.2%) an MLA ⱖ7.5 mm2. Left main coronary artery revascularization was performed in 85.5% (71 of 83) of patients with an MLA ⬍7.5 mm2 and deferred in 86.9% (114 of 131) of patients with an MLA ⱖ7.5 mm2. Longterm follow-up (mean 3.3⫾2.0 years) showed no significant difference in major adverse cardiac events (targetvessel revascularization, acute myocardial infarction, and death) between patients with an MLA ⬍7.5 mm2 who underwent revascularization and those with an MLA ⱖ7.5 mm2 deferred for revascularization (p⫽0.28). Based on outcome, the best cut-off MLA by receiver operating characteristic was 9.6 mm2. Multivariate predictors of cardiac events were age, smoking, and number of non-LMCA vessels diseased. Conclusions: The investigators concluded that IVUS is an accurate method to assess angiographically indeterminate lesions of the LMCA. Perspective: The current study shows that IVUS is a safe method to accurately assess the degree of disease in the LMCA that appears indeterminate by angiography. It also suggests that an IVUS-guided treatment strategy based on deferral of revascularization in patients with MLA ⱖ7.5 mm2 is safe. Based on available data, either IVUS or FFR appears to be a reasonable strategy to define the clinical significance of indeterminate lesions of the LMCA. DM
ACC CURRENT JOURNAL REVIEW May 2005
29