Fadi Matar

Predictors of Coronary Arterial Remodeling Patterns in Patients With Myocardial Ischemia

Preangioplasty intravascular ultrasound in 81 patients showed that adaptive remodeling occurred in 35% and constrictive remodeling in 34%. Multivariate analysis showed that smoking and fibrocalcific plaques were associated with constrictive remodeling, whereas small vessel size and hypercholesterolemia were associated with adaptive remodeling.

The contribution of tissue removal to lumen improvement after directional coronary atherectomy

The contribution of tissue removal to lumen improvement after directional coronary atherectomy remains controversial. The purpose of this study was to validate the intravascular ultrasound measurement of plaque volume and use it to study the contribution of tissue removal to lumen improvement after directional coronary atherectomy. With use of intravascular ultrasound, 12 human coronary vessels were imaged in vitro. With use of computer-assisted planimetry, the external elastic membrane and lumen cross-sectional areas were manually traced and the plaque+media area was calculated at 1 mm axial intervals. Then, plaque+media volume was calculated by Simpsons rule. After imaging, ultrasound measurements of plaque+media volume were compared with histologic measurements. Similarly, volumetric intravascular ultrasound imaging was performed before and after directional atherectomy in 47 patients. In vitro, the mean plaque+media volume measured by intravascular ultrasound was 134.0 +/- 94.8 mm3 and compared well with that derived by histology (187.4 +/- 128.8 mm3, r = 0.96, p < 0.001). In vivo, the lumen volume increased from 27.2 +/- 12.3 to 58.7 +/- 30.3 mm3, and the mean plaque+media volume decreased from 122.0 +/- 74.0 to 97.5 +/- 63.5 mm3. The mean intravascular ultrasound atherectomy index was 76 +/- 23%. In 11 of the 47 patients (23.4%), tissue removal alone accounted for lumen improvement. Volumetric intravascular ultrasound image analysis indicates that the mechanism of directional coronary atherectomy primarily is tissue removal. As a result, the contribution of arterial remodeling (expansion and dissection) probably is less important.

Multivariate predictors of intravascular ultrasound end points after directional coronary atherectomy

OBJECTIVES This study attempted to identify the clinical, angiographic, procedural and intravascular ultrasound predictors of directional atherectomy results assessed by intravascular ultrasound. BACKGROUND Several angiographic and intravascular ultrasound variables have been associated with the outcome of directional coronary atherectomy. No study has incorporated both modalities into a predictive model. METHODS One hundred seventy patients were analyzed using preintervention and postintervention intravascular ultrasound and quantitative angiography. Clinical and procedural variables were collected by independent chart review. Quantitative and qualitative angiographic analysis was performed by a core laboratory in blinded manner. Intravascular ultrasound was performed using a transducer-tipped catheter, rotating within a stationary imaging sheath, and withdrawn automatically at 0.5 mm/s. Clinical, procedural, angiographic and ultrasound variables were tested in a multivariate linear regression model. Dependent ultrasound variables included postatherectomy lumen cross-sectional area and percent cross-sectional narrowing (plaque plus media/external elastic membrane cross-sectional area) and, in a subgroup of 47 patients studied using volumetric analysis, percent plaque volume removal. RESULTS By multivariate stepwise linear regression analysis, predictors of residual lumen cross-sectional area (correcting for reference lumen area) included arc of calcium and preatherectomy plaque plus media cross-sectional area; predictors of residual cross-sectional narrowing were arc of calcium, preatherectomy plaque plus media cross-sectional area and lesion length; and predictors of percent plaque volume removal were arc of calcium and atherectomy device size. CONCLUSIONS The preintervention lesion arc of calcium measured by intravascular ultrasound is the most consistent predictor of the effectiveness and results of directional coronary atherectomy.

Clinical and angiographic outcome after directional coronary atherectomy: A qualitative and quantitative analysis using coronary arteriography and intravascular ultrasound☆

To assess clinical and angiographic outcome after directional coronary atherectomy, the clinical course of 306 patients undergoing this procedure was reviewed. Directional atherectomy was successful in 290 (94.8%) procedures; complications developed in 8 (2.6%) patients. After atherectomy, percent diameter stenosis was reduced from 71 +/- 14 to 14 +/- 14% (p < 0.001) and minimal lumen diameter was increased from 0.87 +/- 0.42 to 2.55 +/- 0.57 mm (p < 0.001). In 128 (42%) patients, adjunct balloon angioplasty was performed to treat either complications or a residual stenosis > 30%. Intravascular ultrasound was also performed in 57 patients after directional atherectomy and demonstrated that a significant amount of residual plaque mass remained in lesions with a calcium arc > or = 90 degrees (17 +/- 5 mm2 vs 12 +/- 5 mm2 in lesions without calcium; p = 0.007). During the 11 +/- 6 month follow-up period, 69 (28.3%) patients developed recurrent clinical events (death, 5; Q wave myocardial infarction, 8; coronary bypass surgery, 31; coronary angioplasty, 36). Using a proportional hazards model, independent predictors of late clinical events included diabetes mellitus (relative risk [RR] = 1.95; p < 0.05), unstable angina (RR = 2.78; p < 0.005) and a prior history of restenosis (RR = 2.21; p < 0.01). We conclude that directional atherectomy is associated with high procedural success rates and infrequent complications in selected lesions subsets, although the degree of plaque resection may be limited if extensive calcium is present. Late clinical events develop in some (28%) patients after directional atherectomy, related to certain preprocedural clinical risk factors.

The State of the Absorb Bioresorbable Scaffold: Consensus From an Expert Panel

Significant progress has been made in the percutaneous coronary intervention technique from the days of balloon angioplasty to modern-day metallic drug-eluting stents (DES). Although metallic stents solve a temporary problem of acute recoil following balloon angioplasty, they leave behind a permanent problem implicated in very late events (in addition to neoatherosclerosis). BRS were developed as a potential solution to this permanent problem, but the promise of these devices has been tempered by clinical trials showing increased risk of safety outcomes, both early and late. This is not too dissimilar to the challenges seen with first-generation DES in which refinement of deployment technique, prolongation of dual antiplatelet therapy, and technical iteration mitigated excess risk of very late stent thrombosis, making DES the treatment of choice for coronary artery disease. This white paper discusses the factors potentially implicated in the excess risks, including the scaffold consideration and deployment technique, and outlines patient and lesion selection, implantation technique, and dual antiplatelet therapy considerations to potentially mitigate this excess risk with the first-generation thick strut Absorb scaffold (Abbott Vascular, Abbott Park, Illinois). It remains to be seen whether these considerations together with technical iterations will ultimately close the gap between scaffolds and metal stents for short-term events while at the same time preserving options for future revascularization once the scaffold bioresorbs.

Adjunctive abciximab improves outcomes during recanalization of totally occluded saphenous vein grafts using transluminal extraction atherectomy.

Degenerative disease of aortocoronary saphenous vein grafts is a major cause of late morbidity and mortality in patients after coronary bypass surgery. We previously described a technique for recanalization of totally occluded grafts using extraction atherectomy (TEC) as a primary modality. While success was comparable to overnight urokinase, distal embolization, no‐reflow, and non‐Q myocardial infarction were common. Recently, abciximab has been used adjunctively in angioplasty and stenting with a reduced incidence of periprocedural complications. In order to determine whether abciximab can reduce the incidence of distal embolization, no‐reflow, and myocardial infarction during TEC in totally occluded saphenous vein grafts, we compared patients treated with adjunctive abciximab with control subjects not receiving the drug. Male patients with previous coronary bypass surgery, class III–IV angina, and totally occluded saphenous vein grafts serving a vascular territory with ischemia not approachable by standard catheter‐based techniques underwent TEC with or without adjunctive abciximab. Recanalization of the graft was achieved in 8/10 (80%) of subjects without abciximab, but complete success was achieved in only 5/10 (50%). In contrast, all procedures in the abciximab group were completely successful, without embolization or no‐reflow. Our results suggest that TEC with adjunctive abciximab may be a highly effective approach for management of totally occluded saphenous vein grafts. Cathet. Cardiovasc. Intervent. 46:107–110, 1999.

Legionella pericarditis diagnosed by direct fluorescent antibody staining

Legionella pericarditis is a rare and serious manifestation of Legionnaires disease. A case is presented in which the diagnosis was established by direct fluorescent antibody staining on a pericardial tissue specimen. Video-assisted thoracoscopy was used safely and effectively in diagnosis and management in this case.

One-Year Follow-Up of Recanalization of Totally Occluded Aortocoronary Saphenous Vein Grafts Using Transluminal Extraction Atherectomy

Recanalization of totally occluded aortocoronary saphenous vein grafts with extraction atherectomy was successful in 80% of patients. Whereas all patients with unsuccessful procedures were dead at 1 year, 75% of those with successful procedures are alive and free of events.

When should fractional flow reserve be performed to assess the significance of borderline coronary artery lesions: Derivation of a simplified scoring system

OBJECTIVES To derive a simplified scoring system (SSS) that can assist in selecting patients who would benefit from the application of fractional flow reserve (FFR). BACKGROUND Angiographers base decisions to perform FFR on their interpretation of % diameter stenosis (DS), which is subject to variability. Recent studies have shown that the amount of myocardium at jeopardy is an important factor in determining the degree of hemodynamic compromise. METHODS We conducted a retrospective multivariable analysis to identify independent predictors of hemodynamic compromise in 289 patients with 317 coronary vessels undergoing FFR. A SSS was derived using the odds ratios as a weighted factor. The receiver operator characteristics curve was used to identify the optimal cutoff (≥3) to discern a functionally significant lesion (FFR≤0.8). RESULTS Male gender, left anterior descending artery apical wrap, disease proximal to lesion, minimal lumen diameter and % DS predicted abnormal FFR (≤0.8) and lesion location in the left circumflex predicted a normal FFR. Using a cutoff score of ≥3 on the SSS, a specificity of 90.4% (95% CI: 83.0-95.3) and a sensitivity of 38.0% (95% CI: 31.5-44.9) was generated with a positive predictive value of 89.0% (95% CI: 80.7%-94.6%) and negative predictive value of 41.6% (95% CI: 35.1%-48.3%). CONCLUSIONS The decision to use FFR should be based not only on the % DS but also the size of the myocardial mass jeopardized. A score of ≥3 on the SSS should prompt further investigation with a pressure wire.

Synergism of rheolytic thrombectomy and embolic distal protection using the percusurge guardwire for fresh thrombus removal: An in vitro study

OBJECTIVES: To test the effectiveness of Rheolytic Thrombectomy (RT) and distal protection balloon wires when used synergistically in an in vitro model. BACKGROUND: Although effective, currently available technologies may not be individually ideal for fresh clots removal. METHODS: Fourteen, fresh blood samples were placed in 14 plastic tubes and left to clot for 6 h. A Percusurge Guardwire balloon was inflated distal to the clot and aspiration was performed using RT in seven tubes and manual aspiration (MA) with the Export catheter in seven tubes. The residual clot in each tube was dried and weighed. Both aspiration systems were advanced over the Guardwire. RESULTS: During RT, none of the protection balloons ruptured and no retrograde clot embolization were observed. MA was most effective when the Export catheter tip was not in direct contact with the clot. The residual clot mass post RT was significantly less than post MA (9.7±2.2 versus 59.2±45.9, P = 0.01). CONCLUSION: RT is compatible with Distal Protection Balloon Wires and results in more complete clot removal than manual aspiration with the export catheter. Although manual aspiration results in a large variation in extraction efficacy, it is most effective when direct catheter‐clot contact is kept to a minimum.