Randomized trial of standard versus ClearWay-infused abciximab and thrombectomy in myocardial infarction: rationale and design of the COCTAIL II study

A comparison of intracoronary treatment strategies for thrombus burden removal during primary percutaneous coronary intervention: a COCTAIL II substudy

BACKGROUND

Manual thrombus aspiration and local drug delivery of abciximab have been proposed as a strategy to reduce thrombus burden during percutaneous coronary intervention in patients with ST elevation myocardial infarction; however, the effectiveness of these approaches, is uncertain. In this COCTAIL II substudy, we compared the effect of these strategies on prestenting and poststenting thrombus burden assessed by optical coherence tomography.

PATIENTS AND METHODS

COCTAIL II trial enrolled patients with ST elevation myocardial infarction randomized to intralesion (IL, by the ClearWay catheter) versus intracoronary (IC, by the guide catheter) abciximab bolus with or without aspiration thrombectomy (AT). The following parameters were used to quantify atherothrombotic burden: thrombus volume (TVol), maximum thrombus area (TA), and thrombus burden (TB). Primary endpoint was the comparison of prestenting TVol after the use of local drug delivery (group IL+IL abciximab plus AT) versus nonlocal drug delivery (group IC abciximab plus AT+IC).

RESULTS

The final population consisted of 59 patients undergoing both prestenting and poststenting optical coherence tomography assessment. The amount of thrombus was not significantly different in the groups with local drug delivery of abciximab versus nonlocal drug delivery in both prestenting (TVol: 18.87±26.70 vs. 19.02±18.45; TB: 26.73±12.8 vs. 25.18±13.25; and maximum TA: 59.25±18.84 vs. 53.34±19.30) and poststenting (TVol: 8.46±9.15 vs. 8.05±6.81; TB: 6.68±3.54 vs. 6.24±3.66; and maximum TA: 15.47±7.61 vs. 16.52±11.55) evaluations. A good correlation between thrombus measurements after thrombus removal techniques and intrastent thrombus was observed.

CONCLUSION

Either local drug delivery of abciximab or manual thrombus aspiration showed comparable results in terms of prestenting and poststenting thrombus burden removal.

The role of residual intrastent thrombus during primary angioplasty: insights from the COCTAIL II study

AIMS

Recent frequency-domain optical coherence tomography studies showed that a complete removal of thrombotic materials is rarely achieved after percutaneous coronary interventions for ST segment elevation myocardial infarction. Residual intrastent thrombus can embolize distally leading to microcirculatory injury. The aim was to find a possible correlation between residual intrastent thrombus and angiographic indexes of myocardial reperfusion.

METHODS

The population consisted of 128 ST segment elevation myocardial infarction patients enrolled in the COCTAIL II trial. Intrastent thrombus at optical coherence tomography was defined as the maximum percentage value of thrombus area (thrombus area/stent area × 100 in the cross-section with largest thrombus). A thrombus area of at least 16% (mean value) was considered indicative of high residual intrastent thrombus. The following angiographic indexes of myocardial reperfusion were evaluated: thrombolysis in myocardial infarction (TIMI) value, corrected TIMI frame count and myocardial blush grade.

RESULTS

Angiographic and optical coherence tomography results are available in 119 patients: 64 had a maximum percentage value of thrombus area less than 16%, whereas the remaining 55 had a residual intrastent thrombus at least 16%. No differences were found regarding the microcirculatory indexes at baseline angiogram. After intervention, patients with intrastent thrombus less than 16% showed a significant improvement in the final TIMI value (2.87 ± 0.33 vs 2.67 ± 0.54; P = 0.014), final TIMI frame count (11.71 ± 4.58 vs 18.04 ± 17.32; P = 0.012) and a nonsignificant improvement in the final myocardial blush grade value (2.58 ± 0.58 vs 2.43 ± 0.76; P = 0.255).

CONCLUSION

Data obtained from this ancillary study of the COCTAIL II suggest that the presence of high residual intrastent thrombus in patients undergoing primary angioplasty is associated with worsened final microcirculatory indexes.

No reflow phenomenon in percutaneous coronary interventions in ST-segment elevation myocardial infarction

Percutaneous coronary intervention (PCI) is effective in opening the infarct related artery and restoring thrombolysis in myocardial infarction flow 3 (TIMI-flow 3) in large majority of ST-elevation myocardial infarction (STEMI). However there remain a small but significant proportion of patients, who continue to manifest diminished myocardial reperfusion despite successful opening of the obstructed epicardial artery. This phenomenon is called no-reflow. Clinically it manifests with recurrence of chest pain and dyspnea and may progress to cardiogenic shock, cardiac arrest, serious arrhythmias and acute heart failure. No reflow is regarded as independent predictor of death or recurrent myocardial infarction. No reflow is a multi-factorial phenomenon. However micro embolization of atherothrombotic debris during PCI remains the principal mechanism responsible for microvascular obstruction. This review summarizes the pathogenesis, diagnostic methods and the results of various recent randomized trials and studies on the prevention and management of no-reflow.

Randomized evaluation of intralesion versus intracoronary abciximab and aspiration thrombectomy in patients with ST-elevation myocardial infarction: The COCTAIL II trial

BACKGROUND

Thrombus burden and distal embolization are predictive of no-reflow during primary percutaneous coronary intervention (PCI) in patients with acute ST-elevation myocardial infarction (STEMI). We sought to compare the efficacy of pharmacological and catheter-based strategies for thrombus in patients with STEMI and high atherothrombotic burden.

METHODS

Between January 2012 and December 2013, 128 STEMI patients undergoing primary PCI at 5 centers were randomly assigned in a 2 × 2 factorial design to intracoronary (IC) abciximab bolus (via the guide catheter) versus intralesion (IL) abciximab bolus, each with versus without aspiration thrombectomy (AT). Study end points were residual intrastent atherothrombotic burden, defined as the number of cross-sections with residual tissue area >10% as assessed by optical coherence tomography, and indices of angiographic and myocardial reperfusion.

RESULTS

Residual intrastent atherothrombotic burden did not significantly differ with IL versus IC abciximab (median [interquartile range] 6.0 [1-15] vs 6.0 [2-11], P = .806) and with AT versus no aspiration (6.0 [1-13] vs 6.0 [2-12], P = .775). Intralesion abciximab administration was associated with improved angiographic myocardial reperfusion in terms of thrombolysis in myocardial infarction (TIMI) flow (3 [3-3] vs 3 [2-3], P = .040), corrected TIMI frame count (12 ± 5 vs 17 ± 16, P = .021), and myocardial blush grade (3 [2-3] vs 3 [2-3], P = .035). In particular, IL abciximab was associated with higher occurrence of final TIMI 3 flow (90% vs 73.8%, P = .032) and myocardial blush grade 3 (71.6% vs 52.4%, P = .039). Conversely, AT had no significant effect on indices of angiographic or myocardial reperfusion.

CONCLUSIONS

In patients with STEMI and high thrombotic burden, neither IL versus IC abciximab nor AT versus no aspiration reduced postprocedure intrastent atherothrombotic burden in patients with STEMI undergoing primary PCI. However, IL abciximab improved indices of angiographic and myocardial reperfusion compared to IC abciximab, benefits not apparent with AT.

Complications of intracoronary abciximab bolus-only versus standard protocol during percutaneous coronary intervention in acute coronary syndrome

BACKGROUND

Abciximab reduces major adverse cardiac events in patients with ST elevation myocardial infarction undergoing primary percutaneous coronary intervention (pPCI). Standard protocol is intravenous abciximab bolus during PCI plus abciximab infusion for 12-18 h post pPCI. Intracoronary (IC) abciximab bolus administration results in high local drug concentrations and hence it should have higher antiplatelet effect. In this study, we assess the short-term efficacy and safety of IC compared to IV bolus of abciximab in ACS patients during pPCI.

METHODS

We compared the clinical outcomes between the IC (n = 56) and standard protocol (n = 170) group of patients. Primary endpoints included bleeding/vascular/ischemic complications and MACE.

RESULTS

The two groups were similar with respect to baseline characteristics. IC abciximab bolus only reduced bleeding complications, with no moderate bleed versus 7.2% in standard protocol group (p value 0.04). Ischemic/vascular complications had statistically insignificant difference between the two groups.

CONCLUSION

We found no significant difference between IC abciximab bolus only and standard abciximab therapy in terms of ischemic/vascular complications and MACE. But there was higher risk of moderate bleed in standard therapy group. The IC bolus route of abciximab may be superior to the intravenous route. Prospective randomized trials are warranted to validate these findings.

Spontaneous and procedural plaque embolisation in native coronary arteries: pathophysiology, diagnosis, and prevention

The detachment of atherothrombotic material from the atherosclerotic coronary plaque and downstream embolisation is an underrecognized phenomenon and it causes different degrees of impairment of the coronary microcirculation. During treatment of obstructive atherosclerotic plaque by percutaneous coronary intervention (PCI) distal embolisation (DE) is considered to be inevitable and it is associated with potential clinical and prognostic implications. This review aims to assess the main aspects of both spontaneous and procedural DE, analyze their different pathophysiology, provide specific insights on the main diagnostic tools for their identification, and finally focus on the main strategies for their treatment and prevention.