Samir R. Kapadia

Coronary Plaque Morphology and Frequency of Ulceration Distant From Culprit Lesions in Patients With Unstable and Stable Presentation

Objective—Intravascular ultrasound studies describe ruptured coronary plaques at sites remote from the culprit lesion in patients with acute myocardial infarction (MI), suggesting multifocal plaque vulnerability. However, the role of intravascular ultrasound in the diagnosis of lesion vulnerability before rupture is unclear. Methods and Results—We compared morphology and frequency of ulceration of additional plaques proximal to the culprit lesion in 105 patients treated with emergent stenting during an evolving, acute MI in the CADILLAC study and 92 patients with stable/subacute presentation who underwent elective stenting. Additional plaques proximal to the culprit lesion were found in 52 (50%) and 54 (59%) patients in the acute MI and stable/subacute group, respectively. The prevalence of ulceration was significantly higher in the acute MI than in the stable/subacute group (19% versus 4%; P =0.014). However, there was no significant difference in other morphological lesion characteristics. Conclusions—Additional plaques are frequently found adjacent to the culprit lesions in patients undergoing percutaneous coronary intervention independent of clinical presentation. The increased prevalence of plaque ulceration but otherwise similar morphology of additional lesions in patients with acute MI versus stable/subacute presentation demonstrates the limitations of imaging in the assessment of plaque vulnerability.

Relation of matrix-metalloproteinase 3 found in coronary lesion samples retrieved by directional coronary atherectomy to intravascular ultrasound observations on coronary remodeling.

We investigated the relation between the presence of matrix-metalloproteinases (MMPs) and direction of remodeling in the coronary lesions of 35 patients. Positive arterial remodeling describes a compensatory expansion of the external elastic membrane (EEM) area of atherosclerotic lesions. An association between positive remodeling and unstable clinical presentation has been previously described. However, the pathophysiology of the remodeling process is not completely understood. Preinterventional intravascular ultrasound images and directional atherectomy (DCA) samples were analyzed. The remodeling ratio was calculated as the EEM area at the lesion site divided by the EEM area at the proximal reference. Positive, intermediate, and negative remodeling were defined as ratios of >1.05, 0.95 to 1.05, and <0.95, respectively. The histologic samples were immunostained for MMP-1, -2, -3, and -9. Positive, intermediate, and negative remodeling was present in 15, 7, and 13 lesions, respectively. Mild and intense cell-associated staining for MMP-1 was found in 21 (68%) and 10 (32%) patients, respectively. Staining for MMP-3 was mild in 20 patients (67%) and intense in 10 patients (33%). Immunostaining for MMP-2 and -9 was mild in all samples. Intense staining for MMP-3 was significantly more common in lesions with positive than negative and/or intermediate remodeling (58% vs 17%; p = 0.04; p = 0.053 after adjustment for gender). Thus, in this in vivo intravascular ultrasound and histologic study, increased cell-associated MMP-3 staining was associated with positive arterial remodeling.

Characteristics of atherosclerotic plaque distribution in coronary artery bifurcations: an intravascular ultrasound analysis.

Objective Vessel bifurcations are prone to atherosclerotic plaque accumulation. Using volumetric intravascular ultrasound analysis, we investigated atheroma distribution at human coronary bifurcations in vivo. Methods We analyzed plaque distribution in 49 left anterior descending coronary artery‐diagonal and 20 left circumflex coronary artery‐obtuse marginal bifurcations with <50% angiographic stenosis. Cross‐sections were analyzed at 1mm intervals in segments 5mm proximal and distal from the bifurcation. Planimetry of the lumen and external elastic membrane (EEM) was performed and plaque thickness measured at four different points relative to the branch: 0°, 90°, 180° and 270°. EEM, lumen and plaque volume and percentage plaque burden (plaque volume/EEM volume) were calculated in the proximal and distal segments. The side‐branch take‐off angle was analyzed in the crosssectional images. Results Volumetric analysis showed that EEM, lumen and plaque were larger (P < 0.001) in proximal segments than distal segments, whereas percent plaque burden was similar in these segments. Plaque accumulated on the opposite wall to the flow divider. Plaque distribution tended to be more eccentric in distal segments (P=0.05) compared to proximal segments. In 26 of 69 lesions, an asymmetric side‐branch take‐off was found and was associated with asymmetric plaque distribution compared to those lesions that had a symmetric side‐branch take‐off (P< 0.01). Conclusion We found characteristic patterns of plaque distribution at coronary bifurcations. Proximal segments demonstrated larger plaque volume than distal segments, despite similar percentages of plaque burden. Plaque volume accumulated opposite to the flow divider, especially in distal segments. The side‐branch take‐off angle in the cross‐sectional plane influenced the plaque distribution in bifurcation lesions. Coron Artery Dis

Combined Transapical Transcatheter Aortic Valve Replacement and Thoracic Endovascular Aortic Repair for Severe Aortic Stenosis and Arch Aneurysm

An 83-year-old male with multiple comorbidities presented with critical aortic stenosis and a saccular aortic arch aneurysm. Through a mini thoracotomy, a balloon expandable transcatheter aortic valve was delivered transapically. A thoracic stent graft was then delivered through the prosthetic valve and deployed in the arch, while a covered stent was deployed in the left common carotid artery. Three-year postoperative computed tomography showed a thrombosed arch aneurysm with decreased size. This case demonstrates the feasibility of using combined transapical transcatheter technologies to treat multicomponent disease in a high-risk patient during a single operation.

TAVR AGE PARADOX: THE OLDEST PATIENTS HAVE BETTER THAN EXPECTED OUTCOMES IN THE PARTNER STUDY

Advanced age is associated with higher mortality in conventional risk models, leading to reluctance to operate on elderly patients. A retrospective study of 2,621 patients in the PARTNER studies (2007-2012) undergoing TAVR was performed. Patients were stratified by age (<80, 80 to <90, ≥90).