Impact of Preinterventional Arterial Remodeling on In-Stent Neointimal Hyperplasia and In-Stent Restenosis After Coronary Stent Implantation-An Intravascular Ultrasound Study-

BACKGROUND

Patterns of arterial remodeling during the course of plaque development have been shown to play an important role in both the progression of de novo atherosclerosis and in the restenotic process following coronary intervention. The aim of the present prospective study was to evaluate the effect of pre-interventional arterial remodeling on in-stent neointimal hyperplasia (NIH) and in-stent restenosis (ISR) after stenting.

METHODS AND RESULTS

Pre-interventional arterial remodeling was assessed in 85 native coronary lesions by using intravascular ultrasound (IVUS). The remodeling index (RI) was 1.09+/-0.20 in the positive remodeling (PR)/intermediate remodeling (IR) group and 0.84+/-0.12 in the negative remodeling (NR) group. The plaque plus media cross sectional area (P&M CSA) at pre-intervention and NIH CSA at follow-up in the minimal lumen CSA were significantly larger in the PR/IR group (9.2+/-2.9 mm2 vs 6.2+/-1.8 mm2, 3.3+/-1.2 mm2 vs 1.5+/-0.9 mm2; p = 0.001, p = 0.001, respectively). On 3-dimensional analysis of IVUS images at follow-up, the lumen volume was significantly smaller in the PR/IR group than that in the NR group (62+/-15 mm3 vs 75 +/-20 mm3; p = 0.001), and neointima hyperplasia volume was significantly larger in the PR/IR group than that in the NR group (46+/-15 mm3 vs 26+/-10 mm3; p = 0.001). A significant positive correlation was found between pre-interventional RI and follow-up NIH CSA (r = 0.25, p = 0.022). The incidence of ISR and repeat intervention was significantly higher in the PR/IR group (30.8% vs 18.2%, 28.8% vs 15.2%; p = 0.032, 0.035, respectively).

CONCLUSION

Measuring pre-interventional arterial remodeling patterns by IVUS may be helpful to stratify lesions at high-risk of ISR.

Usefulness of Physical Maneuvers for Prevention of Vasovagal Syncope

BACKGROUND

It is known that approximately two-thirds of patients with vasovagal syncope have prodromal symptoms and when these start, physical maneuvers that can increase venous return may abort the syncopal attack. The aims of this study were to evaluate the effects of 3 physical maneuvers, squatting, leg-crossing with muscle tensing, and handgrip, on improving hemodynamic status, and to compare the effect of each on aborting or preventing vasovagal syncope.

METHODS AND RESULTS

Of 50 patients who underwent the head-up tilt test (HUT) to evaluate syncope, 27 patients with positive HUT were classified as group I (14 men, 13 women; mean age 44.5+/-15.3 years), 23 patients with negative HUT were classified as group II (13 men, 10 women; mean age 41.2 +/-16.7 years), and 21 normal subjects were classified as group III (10 men, 11 women; mean age 28.6+/-6.3 years). The effects of the physical maneuvers were evaluated in 21 patients from group I who underwent a repeat HUT 1 week after the initial test. Leg-crossing significantly increased systolic blood pressure (SBP) in all 3 groups (8.0+/-5.8 mmHg in group I, 7.0+/-8.5 mmHg in group II, 8.7+/-5.7 mmHg in group III; p < 0.05), but not diastolic blood pressure (DBP). Squatting significantly increased SBP and DBP in all 3 groups (7.1 +/-5.1, 4.6+/-5.8 mmHg in group I, 7.8+/-5.9, 4.3+/-4.7 mmHg in group II, 6.5+/-5.0, 3.7+/-3.9 mmHg in group III; p < 0.05). However, handgrip did not exert any significant influence on the hemodynamics in any group nor did heart rate change significantly during the physical maneuvers in any group. During the repeat HUT, prodromal symptoms with hypotension developed in 13 of the 21 patients and of these 5 fainted immediately after and were not able to do the physical maneuvers. Squatting and leg-crossing aborted syncope in 7 of 8 patients, but handgrip aborted syncope in only 1 patient.

CONCLUSION

Squatting and leg-crossing with muscle tensing improved the hemodynamics of normal subjects as well as those of patients with vasovagal syncope. Squatting and leg-crossing can be used as a simple and effective preventive maneuver in patients with vasovagal syncope.

Predictive Factors of Major Adverse Cardiac Events in Acute Myocardial Infarction Patients Complicated by Cardiogenic Shock Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

The aim of this study was to assess in-hospital mortality and major adverse cardiac events (MACE) during long-term clinical follow-up of patients who developed cardiogenic shock (CS) after acute myocardial infarction (AMI) and who underwent primary percutaneous coronary intervention (PCI).

METHODS AND RESULTS

The data from 147 patients with CS after AMI (61.7 +/-10.4 years, M:F =156:99) who underwent primary PCI at Chonnam National University Hospital between January 1999 and December 2002 were analyzed: clinical characteristics, coronary angiographic findings and mortality during admission, and MACE during a 1-year clinical follow-up. Of the enrolled patients, 121 patients survived (group I, M:F =94:27) and 26 died (group II, M:F =14:12) during admission. By binary logistic regression analysis, in-hospital death was associated with low Thrombolysis In Myocardial Infarction (TIMI) flow after coronary revascularization (p=0.02, odds ratio (OR) =1.3). Eighty-nine patients (60.5%) survived without MACE during the 1-year clinical follow-up and MACE was associated with a C-reactive protein (CRP) of more than 1 mg/dl (p=0.002, OR =6.3) and low TIMI flow after coronary revascularization (p<0.001, OR =7.8).

CONCLUSIONS

Primary PCI achieving TIMI 3 flow reduces in-hospital death in AMI with CS. High concentration of CRP and low TIMI flow are associated with MACE during long-term clinical follow-up.

Long-Term Clinical Outcomes of Platelet Glycoprotein IIb/IIIa Inhibitor Combined With Low Molecular Weight Heparin in Patients With Acute Coronary Syndrome

BACKGROUND

Platelet activation and aggregation with resultant arterial thrombus formation play a pivotal role in the pathophysiology of acute coronary syndrome (ACS). In the present study the efficacy of tirofiban, a specific inhibitor of the platelet glycoprotein IIb/IIIa receptor, combined with heparin or low-molecular-weight heparin (dalteparin), was evaluated for the management of ACS.

METHODS AND RESULTS

One hundred and sixty patients (60.9+/-11.1 years, 104 male) with unstable angina or non-ST elevation myocardial infarction and who had ST-T changes and elevated troponin were randomly assigned to 4 groups: group I (n=40: heparin alone), group II (n=40: dalteparin alone), group III (n=40: tirofiban + heparin) and group IV (n=40: tirofiban + dalteparin). The occurrence of major adverse cardiac events (MACE) was compared prospectively during a 6-month clinical follow-up. Percutaneous coronary intervention or coronary artery bypass graft was performed in 32 cases in group I, 29 in group II, 28 in group III and 31 in group IV (p=0.72). Minor bleeding complication developed in 2 patients (5.0%) in group I, 2 (5.0%) in group II, 4 (10.0%) in group III and 3 (7.5%) in group IV (p=0.78). During the follow-up MACE occurred in 10 patients (31.3%) in group I, 9 (31.0%) in group II, 4 (14.3%) in group III and 4 (12.9%) in group IV (p=0.02: Group I and II vs Group III and IV).

CONCLUSIONS

Tirofiban combined with dalteparin was associated with relatively more bleeding complications in the short term, but was effective in reducing the incidence of MACE during long-term clinical follow-up in patients with ACS.

Effect of abciximab-coated stent on in-stent intimal hyperplasia in human coronary arteries

The investigators tested whether abciximab-coated stents prevent neointimal hyperplasia (NIH) formation in coronary de novo lesions. Abciximab-coated stents were compared with control stents. All patients underwent follow-up coronary angiography and intravascular ultrasound (IVUS). All stents were successfully deployed, and patients were discharged home without clinical events. At follow-up coronary angiography, the restenosis rate and late loss were 14% and 0.33 +/- 0.28 mm in the abciximab-coated stent group and 28.6% and 0.64 +/- 0.32 mm in the control stent group (p = 0.099 and p = 0.014, respectively). At follow-up IVUS, the intrastent luminal area and intrastent NIH area were 5.7 +/- 1.6 and 2.0 +/- 1.6 mm(2), respectively, in the abciximab-coated stent group and 4.2 +/- 0.8 and 3.4 +/- 1.7 mm(2), respectively, in the control stent group (p = 0.001 and p = 0.001, respectively). Abciximab-coated stents are feasible and significantly inhibit NIH, with potential therapeutic benefit in preventing stent restenosis.

Effect of Combined Intracoronary Adenosine and Nicorandil on No-Reflow Phenomenon During Percutaneous Coronary Intervention

BACKGROUND

This study aimed to clarify the effect of intracoronary administration of combined adenosine and nicorandil on the no-reflow phenomenon.

METHODS AND RESULTS

Fifty patients (67+/-10 years, 30 male) with acute myocardial infarction (AMI) who developed no-reflow phenomenon during primary percutaneous coronary intervention (PCI) between June 2001 and May 2003 comprised the study group, which was divided into 2 groups: group I [25 patients, 67+/-10 years, 13 male; adenosine (24 microg/ml) alone in addition to nitrate] and group II [25 patients, 66+/-9 years, 17 male; combined intracoronary administration of adenosine and nicorandil (2 mg/ml) in addition to nitrate]. In-hospital and 6-month major adverse cardiac events (MACE) after PCI were compared between the 2 groups. Risk factors of coronary disease, left ventricular ejection fraction and wall motion score were not significantly different between the 2 groups (p=NS). Time interval from the onset of chest pain to PCI, number of involved vessels, lesion type according to ACC/AHA classification and TIMI flow grade (TFG) were not significantly different in both groups (p=NS). Incidence of thrombosis or dissection after balloon angioplasty, diameter and length of stent, and use of Reopro during PCI were not significantly different. TFG after PCI (2.0+/-0.9 vs 2.6+/-0.6, p=0.024), DeltaTFG (1.5+/-1.1 vs 2.2+/-1.0, p=0.033) and difference in TIMI frame count (TFC) before and after PCI (DeltaTFC) were greater in group II than group I (45.2+/-24.5 vs 63.6+/-23.2, p=0.014). Myocardial blush score 3 was obtained more frequently in group II than group I (44% vs 76%, p=0.014). In-hospital death did not occur in any of group II, but 4 patients of group I died (p=0.043). Two cases of MACE developed in each group and heart failure occurred in 3 (12%) of group I and 1 (4%) of group II patients during the 6-month follow-up (p=NS).

CONCLUSIONS

Intracoronary administration of adenosine combined with nicorandil may improve both the occurrence of no-reflow in patients during PCI for AMI and short-term clinical outcome, compared with adenosine alone.