Adjunctive Catheter-Directed Thrombolysis during Primary PCI for ST-Segment Elevation Myocardial Infarction with High Thrombus Burden

Background: High coronary thrombus burden has been associated with unfavorable outcomes in patients with ST-segment elevation myocardial infarction (STEMI), the optimal management of which has not yet been established. Methods: We assessed the adjunctive catheter-directed thrombolysis (CDT) during primary percutaneous coronary intervention (PCI) in patients with STEMI and high thrombus burden. CDT was defined as intracoronary infusion of tissue plasminogen activator (t-PA; monteplase). Results: Among the 1849 consecutive patients with STEMI, 263 had high thrombus burden. Moreover, 41 patients received t-PA (CDT group), whereas 222 did not receive it (non-CDT group). No significant differences in bleeding complications and in-hospital and long-term mortalities were observed (9.8% vs. 7.2%, p = 0.53; 7.3% vs. 2.3%, p = 0.11; and 12.6% vs. 17.5%, p = 0.84, CDT vs. non-CDT). In patients who underwent antecedent aspiration thrombectomy during PCI (75.6% CDT group and 87.4% non-CDT group), thrombolysis in myocardial infarction grade 2 or 3 flow rate after thrombectomy was significantly lower in the CDT group than in the non-CDT group (32.2% vs. 61.0%, p < 0.01). However, the final rates improved without significant difference (90.3% vs. 97.4%, p = 0.14). Conclusions: Adjunctive CDT appears to be tolerated and feasible for high thrombus burden. Particularly, it may be an option in cases with failed aspiration thrombectomy.

Aspiration thrombectomy using a novel 088 catheter and specialized delivery catheter

BackgroundWe describe the first-in-human experience using the Route 92 Medical Aspiration System to perform thrombectomy in the initial 45 consecutive stroke patients enrolled in the SUMMIT NZ trial. This aspiration system includes a specifically designed delivery catheter which enables delivery of 0.070 inch and 0.088 inch aspiration catheters.MethodsThe SUMMIT NZ trial is a prospective, multicenter, single-arm study with core lab imaging adjudication. Patients presenting with acute ischemic stroke from large vessel occlusion are eligible to enrol. The study has had three phases which transitioned from use of the 0.070 inch to the 0.088 inch catheter.ResultsVessel occlusions were located in the internal carotid artery (27%), M1 (60%) and M2 (13%). Median baseline National Institutes of Health Stroke Scale (NIHSS) was 16 (IQR 10). Across the three phases, the first-pass reperfusion rate of modified Thrombolysis In Cerebral Infarction (mTICI) ≥2b was 62% using the Route 92 Medical system; this rate was 29% in phase 1, 56% in phase 2, and 80% in phase 3. The first-pass reperfusion rate of mTICI ≥2c was 42% overall, 29% in phase 1, 33% in phase 2%, and 55% in phase 3. A final reperfusion rate of mTICI ≥2b was achieved in 96% of cases, with 36% of cases using adjunctive devices. Patients had an average improvement of 6.7 points in NIHSS from baseline at 24 hours, and at 90 days 48% were functionally independent (modified Rankin Scale 0–2).ConclusionsIn this early experience, the Route 92 Medical Aspiration System has been effective and safe. The system has design features that improve catheter deliverability and have the potential to increase first-pass reperfusion rates in aspiration thrombectomy.

The Q and A—The MIVI Q Catheters for Aspiration Thrombectomy—Initial Experience from London

Background: Aspiration thrombectomy is a widely accepted treatment option for large vessel occlusion (LVO). The MIVI aspiration system has a novel design to maximize the lumen size. We present the results of our initial experience with this innovative aspiration thrombectomy system. Materials and Methods: Retrospectively, we reviewed our database to find all cases of LVO treated with the MIVI Q system (February 2019 and July 2020). In addition, we recorded the baseline demographics, NIHSS, ASPECT, mTICI scores, procedural time, complications, and 90 day mRS. Results: Herein, we identified 25 patients with an average age of 65.3 ± 19.3 years (range 19–89), majority of whom were female (n = 14, 56%). The average NIHSS was 16.9 ± 6.7 (range 6–30), and the average CT ASPECT was 7.9 ± 1.4 (range 5–10). The most common clot location was the M1 segment of the MCA (n = 16, 64%). Four of the patients had tandem lesions (16%). The average clot length was 21.7 ± 31 mm (range 2–130 mm). Of the 23 cases where the Q catheter reached the proximal clot face, mTICI ≥ 2b was achieved on the first pass in 11 cases (44%), and at the end of the ‘Q aspiration’ only the procedures with 16 patients achieved mTICI ≥ 2b recanalization (64%). Stent-retrievers were used in 13 cases (52%). At the end of the procedure, 24 patients (96%) achieved mTICI ≥ 2b with 18 patients (72%) achieving mTICI ≥ 2c. The average number of passes with the Q catheter, including when it was used for SOLUMBRA, was 2.1 ± 2.2 (range 1–10). The mean procedure time was 69 ± 32 mins (range 7–116 mins). No complications were associated with the MIVI Q. Conclusions: The MIVI aspiration system is a novel technology with regards to aspiration mechanical thrombectomy. The system is easy to use with early results comparable to other large-bore catheter systems. However, further studies are needed.

Abstract 17117: Hyperhomocysteinemia Associated St Elevation Myocardial Infarction In A Young Male

Case Presentation: A 24-year-old male with a medical history of Crohn’s on mesalamine presented to the emergency room with crushing substernal chest pain at rest. Electrocardiogram revealed ST elevations in Lead V2-V5 (Figure-1a). He was taken emergently to the catheterization laboratory and had 100% thrombotic occlusion of his proximal left anterior descending coronary artery (LAD) (Figure-1b). Intravascular ultrasound (IVUS) confirmed the presence of soft atheromatous lipid-rich plaque in the proximal LAD with heavy thrombus burden (Figure-1c/d). He underwent aspiration thrombectomy and IVUS guided percutaneous coronary intervention with a 4.5 mm x 32 mm drug-eluting stent. Echocardiogram revealed an akinetic anterior wall with an ejection fraction of 35% without a patent foramen ovale. Hypercoagulable workup was initiated and showed a significantly elevated homocysteine level of 84.4 umol/L (normal:3.5-10.4). Family history, drug screen, hemoglobin A1C, and lipid profile were unremarkable. Discussion: The differential diagnosis in a young male presenting with a STEMI includes thromboembolism versus plaque rupture. IVUS showed clear evidence of a lipid-rich plaque demonstrating premature atherosclerotic vascular disease rather than a thromboembolic event. His most striking risk factor was hyperhomocysteinemia with a level of 84.4 umol/L. Elevations in homocysteine plasma concentration has been identified as an independent risk factor for atherosclerosis due to its atherogenic and prothrombotic properties. To date lowering homocysteine levels with folate and additional therapies have not shown to reduce the risk of coronary disease. Our case stresses the importance of intravascular imaging, especially in atypical cases such as a young male presenting with a STEMI to differentiate plaque rupture versus thromboembolism. Further studies are needed to identify risk modifying therapies for hyperhomocysteinemia associated vascular disease.

Successful endovascular treatment for acute renal artery occlusion

Purpose: We report a case of revascularization for a totally occluded renal artery using endovascular renal thrombus aspiration followed by catheter-directed thrombolysis.Case Report: A 56 years old man presented with sudden onset of severe left-sided abdominal and loin pain for six hours. Urgent computed tomography angiogram showed total occlusion of left renal artery. Emergency selective left renal angiogram and thrombus aspiration using a 5-French Cobra catheter was performed. Catheter-directed thrombolysis with urokinase was initiated after aspiration thrombectomy. Angiogram 24 hours after thrombolysis showed the left renal artery and its segmental branches were successfully revascularized. Patient was on anticoagulation after operation and his renal function recovered well.Conclusion: Percutaneous aspiration thrombectomy combined with intra-arterial local fibrinolysis are effective in the salvage of renal function.