Francesco LiistroCardiovascular Department, Arezzo, Italy

Impact of Thrombus Aspiration on Myocardial Tissue Reperfusion and Left Ventricular Functional

Recovery and Remodeling after Primary Angioplasty

BACKGROUNDBACKGROUND

Mounting interest has emerged regarding the role of distal embolization as a major determinant of impaired myocardial perfusion after primary PCI

Previous trials have shown the feasibility of thrombus aspiration during primary PCI and its impact on outcome

However, whether improvements in myocardial reperfusion with thrombus aspiration are directly connected to better follow-up left ventricular function and geometry, features which are strongly related to short and long-term mortality, has not been clarified so far

Mounting interest has emerged regarding the role of distal embolization as a major determinant of impaired myocardial perfusion after primary PCI

Previous trials have shown the feasibility of thrombus aspiration during primary PCI and its impact on outcome

However, whether improvements in myocardial reperfusion with thrombus aspiration are directly connected to better follow-up left ventricular function and geometry, features which are strongly related to short and long-term mortality, has not been clarified so far

Single center, prospective, randomized studyConsecutive patients with ST elevation acute MI

Primary endpoint: ST-segment elevation resolution (STR)

Secondary endpoints: TIMI Myocardial Perfusion Grade (TMPG) TIMI grade flow Corrected TIMI Frame Count (cTFC) Contrast enhancement by intracoronary myocardial contrast echo

(MCE) Persistent ST-segment deviation Time-course of wall motion score index, LV ejection fraction and

volumes

METHODS METHODS

Inclusion Criteria• symptoms suggesting acute myocardial ischemia

lasting more than 30’ • onset of symptoms < 12 hours • ST-segment elevation > 0.1 mV in two or more leads

Exclusion criteria• rescue PCI after thrombolysis• absence of an optimal echocardiographic apical view• life expectancy < 6 months

METHODS METHODS

111 Consecutive Patients with ST-segment elevation Myocardial Infarction within 12 hours of symptoms onset undergoing primary PCI

Patients

Randomization 1:1

PCI

Standard PCI(n=56)

EXPORT (Medtronic®)(n=55)

Angioplasty: TIMI flow gradecTFCTIMI Myocardial Perfusion GradeIntracoronary MCE

Evaluation of regional (WMSI) and global (EF) LV function and volumes (EDVI and ESVI) within 24 hoursECG (baseline, 90 min, 6 hours)

Post-PCI

Evaluation of regional (WMSI) and global (EF) LV function and volumes (EDVI and ESVI)Clinical follow-up for all patients

6-monthsFollow-Up

TRIAL FLOW CHARTTRIAL FLOW CHART

Control56 patients

N°(%) or M±SD

Export55 patients

N°(%) or M±SDP

value

Male sex 43 (77) 43 (78) >0.9

Age 65±11 64±11 0.7

Current smoker 36 (64) 35(63) >0.9

Diabetes 7(12) 11(20) 0.2

Family history of CAD 13 (23) 21 (38) 0.1

Hypertension 30 (53) 33 (60) 0.5

Hypercholesterolemia 17(30) 19(34) 0.6

History of CAD 2(4) 4(8) 0.1

Creatinine (mg/dL) 1.0±0.2 0.9±0.1 0.2

Killip Class ≥ 3 4(8) 2(4) 0.1

Symptom-onset-to-balloon time (min) 209±147 189±105 0.3

Symptoms-to-door time (min) 141.6±140.1 112.6±97.6 0.2

Door-to-balloon time (min) 75.9±38.7 75.7±33 >0.9

ST Segment elevation (mm) 8.1±5.4 8.5±5.8 0.7

ST Segment Deviation (mm) 11.6±7.9 12.7±7.8 0.5

Baseline clinical characteristicsBaseline clinical characteristics

 

Control56 patients

N°(%) or M±SD

Export55 patients

N°(%) or M±SD P value

Multivessel disease 21(40) 26(47) 0.4

Infart Related Artery (IRA):

LAD 26 (46) 21 (38) 0.1

CX 7(13) 6(11) 0.2

RCA 23(41) 28(51) 0.1

Lesion length (mm) 13.3±5.5 13.2±4.5 0.9

RVD (mm) 2.97±0.44 2.97±0.38 0.9

Basal MLD (mm) 0.03±0.14 0.01±0.06 0.2

Final MLD (mm) 2.86±0.6 2.91±0.4 0.1

Baseline TIMI-0-1 43(76) 38(69) 0.4

Stented patients 56(100) 55(100) >0.9

Direct Stenting 5(9) 12(21) 0.1

Complete revascularization 35(62) 29(53) 0.3

Distal Embolization 14(25) 4(7) 0.01

Final TIMI 3 46(82) 53(96) 0.02

Corrected TIMI Frame Count 25.9±12.4 21.6±9.7 0.04

Angiographic no reflow 10(18) 2(4) 0.02

Angiographic and Procedural CharacteristicsAngiographic and Procedural Characteristics

Tissue level perfusion

RESULTSRESULTS

Control

Thrombus-Aspiration

Myocardial Contrast Echocardiography

RESULTSRESULTS

Control

Thrombus-Aspiration

Time Course of Changes in Left Ventricular Ejection Fraction in the two study groups

RESULTSRESULTS

*P value according to repeated-measures ANOVA

*p<0.0001

Time Course of Changes in Wall Motion Score Index in the two study groups

RESULTSRESULTS

*P value according to repeated-measures ANOVA

Time Course of Changes in Left Ventricular End Diastolic Volume Index in the two study groups

RESULTSRESULTS

*p=0.001

*P value according to repeated-measures ANOVA

Time Course of Changes in Left Ventricular End Sistolic Volume Index in the two study groups

RESULTSRESULTS

*p<0.001

*P value according to repeated-measures ANOVA

6-months clinical follow-up

 

Control56 patients

N°(%)

Export55 patients

N°(%) P value

Cardiac Death 0 1(2) 0.5

Re-Myocardial Infarction 3(5) 3(5) >0.9

Stent Acute Thrombosis 2(3.5) 1(1.8) >0.9

Ischemia Driven TLR 4(7) 4(7) >0.9

MACE 7(12) 8(14) 0.8

6-months re-admission for congestive HF 3(5) 0 0.2

RESULTSRESULTS

Manual thrombus aspiration in the setting of primary PCI improves myocardial reperfusion as assessed by myocardial blush, myocardial contrast enhancement by intracoronary MCE and ST-segment resolution.

The improvement in tissue-level perfusion is paralleled by a significant improvement in regional and global LV function and a significant reduction of LV remodeling at 6 months.

This study provides the pathophysiological missing link between thrombus removal, tissue level perfusion, LV remodeling and clinical outcome.

CONCLUSIONSCONCLUSIONS