Abstract
Background
Manual thrombus aspiration improves the efficacy of percutaneous coronary interventions (PCIs) in ST-elevation acute myocardial infarction (STEMI). The transradial approach (TRA) is an emerging vascular approach for PCI but is associated with specific technical requirements. As data on the combination of thrombus aspiration and TRA are scarce, we sought to assess the feasibility of TRA manual thrombus aspiration in STEMI patients.
Methods
All consecutive patients treated with manual thrombectomy for acute STEMI in three Italian hospitals were considered. Patients were divided according to the vascular approach into two groups: TRA and transfemoral (TFA). Two primary end points were defined: thrombectomy feasibility (ability to cross the occlusion with the device) and thrombectomy efficacy (absolute thrombus score reduction after device crossing).
Results
From January 2008 to December 2009, 303 patients were included: 151 patients (63±13 years) were treated through TFA, and 152 patients (61±12 years, P =.25) were treated through TRA. There were no significant differences in thrombectomy feasibility (75% in the TRA compared to 74.8% in the TFA group, P =.97) or in thrombectomy efficacy (2.6±.8 for TRA and 2.9±2 for TFA, P =.15). In both groups, there was a significant reduction in thrombus score after manual thrombus aspiration. Angiographically evident distal embolization after device crossing was low and observed in seven cases (5%) either for TFA and TRA ( P =.99).
Conclusions
The present study suggests that, in the setting of acute STEMI, manual thrombus aspiration through TRA is feasible, and its efficacy is comparable to the TFA.
1
Introduction
Manual thrombectomy during percutaneous coronary interventions (PCIs) for ST-elevation acute myocardial infarction (STEMI) is associated with reduced infarct area and better ST segment resolution . Moreover, one large randomized study and a patient-level pooled analysis of 11 trials showed a significant mortality reduction with thrombectomy compared to conventional PCI in the treatment of STEMI patients .
The transradial approach (TRA) represents a good alternative to the transfemoral approach (TFA) for PCI and is associated with lower bleeding complications . Moreover, some studies showed the feasibility of TRA for the percutaneous treatment of STEMI. However, there are some concerns about the feasibility of the use of adjunctive devices during PCI for acute STEMI through TRA, and there are no reports defining the use of thrombectomy for acute STEMI through TRA.
The aim of this study was to evaluate the feasibility of manual thrombectomy for STEMI patients treated by PCI through TRA compared to TFA.
2
Methods
From January 2008 to December 2009, all consecutive patients treated with thrombectomy for acute STEMI during percutaneous coronary interventional procedures in three Italian hospitals were recruited in this multicenter registry ( Fig. 1 ).
STEMI was defined as ST-elevation of 1 mm or more in two or more contiguous leads or new left bundle-branch block within 24 h after the onset of chest pain. The vascular access (transradial or transfemoral) for the procedure was left to the operator’s discretion. All patients were treated according to standard guidelines with aspirin (500 mg of chewable preparation as loading dose followed by 100 mg/day), clopidogrel (300 mg as loading dose and then 75 mg/day), and unfractionated heparin (5000 U as loading dose and then 1000 U/kg/h with activated Partial Thromboplastin Time in the range of 50–70 s). The use of the glycoprotein IIb/IIIa inhibitors during the procedure was left to the operator’s discretion.
Thrombus aspiration was performed using standard thrombus-aspirating catheters previously used in randomized trials (Export Aspiration Catheter, Medtronic Inc., Minneapolis, MN, USA, and Diver CE, Invatec, Roncadelle, Italy).
In the TRA group, the Allen test was performed prior to the procedure, and the radial artery approach was performed using a hydrophilic guidewire and hydrophilic sheath (Radifocus, Introducer II, Terumo Corporation, Tokyo, Japan). Arterial sheaths were removed immediately after procedures, and hemostasis was obtained according to the standard of the center involved using an inflatable wrist band (TR-BAND, Terumo Corporation, Tokyo, Japan) or a pressure bandage with three elastic sticky straps.
In the TFA group, a nonhydrophilic sheath (Avanti+, Cordis Corporation, Miami Lakes, FL, USA) was utilized. Arterial sheaths were removed after procedures according to activated clotting times (<180 s), and hemostasis was obtained by manual compression, lasting at least 20 min, and subsequent femoral bandage.
All patients provided written informed consent to the procedure, and ethical committee approval was waived given the observational design of the study.
2.1
Angiographic analyses
Coronary angiograms before intervention, after thrombus aspiration, and at the end of the procedure were reviewed and analyzed by a single cardiologist (G.P.), who not involved in the enrolment of patients, to assess anterograde coronary flow according to the standard Thrombolysis In Myocardial Infarction (TIMI) criteria , the corrected TIMI frame count (cTFC) according to Gibson , thrombus score according to the TIMI study group , myocardial blush grade (MBG) according to van’t Hof , and the occurrence of angiographic distal embolization defined as occlusion with an abrupt “cutoff” appearance on angiography of a branch of the infarct-related artery distal to the culprit lesion site. Postprocedural adverse angiographic outcome was defined as the occurrence of final TIMI 0–1 flow and/or angiographically evident distal embolization.
2.2
End point
Two primary end points were defined: the thrombectomy feasibility (defined as ability to cross the occlusion with the device and expressed as percentage of successful crossing) and thrombectomy efficacy (defined as absolute thrombus score reduction after device crossing compared to baseline and expressed as mean±standard deviation). All unsuccessful attempts to cross the lesion with the manual thrombectomy device were documented, and the analysis of thrombus score reduction after catheter crossing was limited only to cases with successful crossing. Secondary end points were in-hospital death, bleeding complications, postprocedural TIMI flow, TIMI frame count, and MBG. Bleeding complications were classified according to the TIMI classification as major and minor .
2.3
Statistical analysis
Continuous variables for each of the two subject groups were reported as mean and standard deviation for variables normally distributed and as median with interquartile range for those not normally distributed and were compared using Student’s t test or Mann–Whitney U test as appropriate. Analysis of variance with the Bonferroni correction was used to assess multiple comparisons. Categorical variables were indicated as the absolute number and percentage and were compared by Pearson χ 2 test or, if the number expected of patients was less than five, with the Fisher’s Exact Test. A two-tailed P value of ≤.05 was considered statistically significant. Statistica for Windows (version 10.0, Statsoft, Inc.) software was used for all analyses.
2
Methods
From January 2008 to December 2009, all consecutive patients treated with thrombectomy for acute STEMI during percutaneous coronary interventional procedures in three Italian hospitals were recruited in this multicenter registry ( Fig. 1 ).
STEMI was defined as ST-elevation of 1 mm or more in two or more contiguous leads or new left bundle-branch block within 24 h after the onset of chest pain. The vascular access (transradial or transfemoral) for the procedure was left to the operator’s discretion. All patients were treated according to standard guidelines with aspirin (500 mg of chewable preparation as loading dose followed by 100 mg/day), clopidogrel (300 mg as loading dose and then 75 mg/day), and unfractionated heparin (5000 U as loading dose and then 1000 U/kg/h with activated Partial Thromboplastin Time in the range of 50–70 s). The use of the glycoprotein IIb/IIIa inhibitors during the procedure was left to the operator’s discretion.
Thrombus aspiration was performed using standard thrombus-aspirating catheters previously used in randomized trials (Export Aspiration Catheter, Medtronic Inc., Minneapolis, MN, USA, and Diver CE, Invatec, Roncadelle, Italy).
In the TRA group, the Allen test was performed prior to the procedure, and the radial artery approach was performed using a hydrophilic guidewire and hydrophilic sheath (Radifocus, Introducer II, Terumo Corporation, Tokyo, Japan). Arterial sheaths were removed immediately after procedures, and hemostasis was obtained according to the standard of the center involved using an inflatable wrist band (TR-BAND, Terumo Corporation, Tokyo, Japan) or a pressure bandage with three elastic sticky straps.
In the TFA group, a nonhydrophilic sheath (Avanti+, Cordis Corporation, Miami Lakes, FL, USA) was utilized. Arterial sheaths were removed after procedures according to activated clotting times (<180 s), and hemostasis was obtained by manual compression, lasting at least 20 min, and subsequent femoral bandage.
All patients provided written informed consent to the procedure, and ethical committee approval was waived given the observational design of the study.
2.1
Angiographic analyses
Coronary angiograms before intervention, after thrombus aspiration, and at the end of the procedure were reviewed and analyzed by a single cardiologist (G.P.), who not involved in the enrolment of patients, to assess anterograde coronary flow according to the standard Thrombolysis In Myocardial Infarction (TIMI) criteria , the corrected TIMI frame count (cTFC) according to Gibson , thrombus score according to the TIMI study group , myocardial blush grade (MBG) according to van’t Hof , and the occurrence of angiographic distal embolization defined as occlusion with an abrupt “cutoff” appearance on angiography of a branch of the infarct-related artery distal to the culprit lesion site. Postprocedural adverse angiographic outcome was defined as the occurrence of final TIMI 0–1 flow and/or angiographically evident distal embolization.
2.2
End point
Two primary end points were defined: the thrombectomy feasibility (defined as ability to cross the occlusion with the device and expressed as percentage of successful crossing) and thrombectomy efficacy (defined as absolute thrombus score reduction after device crossing compared to baseline and expressed as mean±standard deviation). All unsuccessful attempts to cross the lesion with the manual thrombectomy device were documented, and the analysis of thrombus score reduction after catheter crossing was limited only to cases with successful crossing. Secondary end points were in-hospital death, bleeding complications, postprocedural TIMI flow, TIMI frame count, and MBG. Bleeding complications were classified according to the TIMI classification as major and minor .
2.3
Statistical analysis
Continuous variables for each of the two subject groups were reported as mean and standard deviation for variables normally distributed and as median with interquartile range for those not normally distributed and were compared using Student’s t test or Mann–Whitney U test as appropriate. Analysis of variance with the Bonferroni correction was used to assess multiple comparisons. Categorical variables were indicated as the absolute number and percentage and were compared by Pearson χ 2 test or, if the number expected of patients was less than five, with the Fisher’s Exact Test. A two-tailed P value of ≤.05 was considered statistically significant. Statistica for Windows (version 10.0, Statsoft, Inc.) software was used for all analyses.
3
Results
Of the 303 patients enrolled in this registry, 151 patients underwent manual thrombectomy through TFA and 152 patients through TRA. The clinical characteristics of the two groups are presented in Table 1 and were similar between the two groups except for the presence of significantly more males, heavier subjects, and more current smokers in the TRA compared to the TFA group. Procedural characteristics of the two groups are summarized in Table 2 . In the TRA group, all procedures were performed using a 6-Fr catheter compared to 91% in the TFA group ( P =.001) due to the use in 13 cases of larger-caliber guiding catheters (7 Fr). Most transradial procedures (86%) were performed using the right transradial approach. Fluoroscopy times [median 14 min (10–22 min) and 11 min (8–19 min), respectively; P =.02] as well as the contrast dose (247±106 ml and 205±79 ml, respectively; P =.002) were significantly higher in the TRA compared to the TFA. The higher symptom to balloon time in the transradial group was due to a higher number of patients referred from other hospitals for the treatment of an acute myocardial infarction ( Table 2 ).
| Characteristic | Transradial ( n =152) | Transfemoral ( n =151) | P |
|---|---|---|---|
| Demographics | |||
| Age (years) | 61.3±12 | 62.9±13 | .25 |
| Male, n (%) | 131 (86) | 112 (74) | .009 |
| Height (cm) | 170±9 | 169±9 | .57 |
| Weight (kg) | 82.7±15 | 76.9±14 | .02 |
| Medical history, n (%) | |||
| Previous myocardial infarction | 17 (11) | 17 (11) | .98 |
| Previous PCI | 20 (13) | 17 (11) | .61 |
| Previous CABG | 2 (1) | 3 (2) | .65 |
| Diabetes | 32 (21) | 26 (17) | .41 |
| Hypertension | 89 (59) | 90 (60) | .85 |
| Current smokers | 93 (61) | 73 (48) | .03 |
| Peripheral vascular disease | 4 (3) | 6 (4) | .51 |
| Dyslipidemia | 68 (45) | 64 (42) | .68 |
| Chronic kidney disease | 22 (15) | 20 (13) | .76 |
| Clinical features, n (%) | |||
| Ejection fraction ≤30% | 9 (6) | 6 (4) | .44 |
| Ejection fraction 30%–50% | 56 (37) | 64 (42) | .32 |
| Ejection fraction ≥50% | 87 (57) | 81 (54) | .53 |
| Cardiogenic shock | 18 (12) | 22 (15) | .48 |
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