Radiofrequency-intravascular ultrasound assessment of lesion coverage after angiography-guided emergent percutaneous coronary intervention in patients with non-ST elevation myocardial infarction

Using radiofrequency-intravascular ultrasound (VH-IVUS), we have previously demonstrated that in 50% of patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention with optimal angiographic result, the stent does not fully cover the whole VH-IVUS-derived thin-cap fibroatheroma (VH-TCFA) related to the culprit lesion. Presently, we set out to extend these findings to 20 patients with non-STEMI with Thrombolysis In Myocardial Infarction flow 3 in the infarct-related artery before intervention who were then treated with angiography-guided direct stent implantation. The lesion was imaged with VH-IVUS before and after intervention, but the results were blinded to the operator. Plaque rupture site was identified in 8 lesions (40%), all proximal to the minimum lumen area (MLA) site. The maximum necrotic core site was found proximal to MLA in 18 lesions and at the MLA in 2 lesions. Although the plaque rupture site was fully covered with the stent in all lesions, an uncovered VH-TCFA was found in 7 lesions (35%), 4 in the proximal reference segment, 1 in the distal reference segment, and 2 in both the proximal and distal reference segments. In conclusion, in 35% of patients with non-STEMI undergoing angiography-guided emergent percutaneous coronary intervention, the stent does not fully cover a VH-TCFA related to the culprit lesion.

Rescue removal of disrupted balloon catheter from right coronary artery and aortic arch

We present the case of a 70-year-old female patient diagnosed with unstable angina, who was qualified to coronarography in a peripheral interventional cardiology department. Critical stenosis of right posterior descending artery was found. During percutaneous coronary intervention, after-stent balloon catheter interrupted and was left partially in the right coronary artery sticking out of the aortic arch. In a second attempt at removal, using an Amplatz GooseNeck snare, operators managed to take the broken balloon out of the intravascular space.

Virtual histology-intravascular ultrasound assessment of lesion coverage after angiographically-guided stent implantation in patients with ST Elevation myocardial infarction undergoing primary percutaneous coronary intervention

An occlusion or severe stenosis (angiographic culprit lesion) of the infarct-related artery is frequently located at the site of the maximum thrombus burden, whereas the origin of the plaque rupture (the true culprit) can be situated proximal or distal to it. The aim of this study was to examine stent coverage of true culprit lesions in 20 patients who underwent primary percutaneous coronary intervention and had Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow restored in the infarct-related artery by angiographically guided direct stenting. Images of lesions were obtained using virtual histology-intravascular ultrasound before and after intervention (blinded to the operator). Plaque rupture sites were identified by intravascular ultrasound in 12 lesions (60%), 11 proximal and 1 distal to the minimum luminal area (MLA). Maximum necrotic core sites were found proximal to the MLA in 16 lesions, at the MLA in 3 lesions, and distal to the MLA in 1 lesion. Plaque rupture sites were fully covered by stents in 11 lesions. Virtual histology-intravascular ultrasound-derived thin-cap fibroatheroma longitudinal geographic misses were found in 10 lesions, 7 in the proximal reference segment and in 3 patients in the proximal and distal reference segments. In conclusion, in about 50% of patients who undergo primary percutaneous coronary intervention for ST-segment elevation myocardial infarction with optimal angiographic results, the stent does not fully cover the maximum necrotic core site related to the culprit lesion.

Assessment of Culprit Plaque Temperature by Intracoronary Thermography Appears Inconclusive in Patients With Acute Coronary Syndromes

OBJECTIVE

Safety and feasibility evaluation of intracoronary temperature measurements in patients with acute coronary syndromes (ACS) using a catheter based thermography system.

METHODS AND RESULTS

Thermography was performed in 40 patients with ACS. A 3.5-F thermography catheter containing 5 thermocouples measuring vessel wall temperature, and 1 thermocouple measuring blood temperature (accuracy 0.05 degrees C) was used. Gradient (deltaTmax) between blood temperature (T(bl)) and the maximum wall temperature during pullback was measured. The device showed satisfactory safety in ACS. Only in 16 patients (40%) deltaTmax was > or = 0.1 degrees C. In 23 patients (57.5%) the highest deltaTmax was found in the culprit segment. DeltaTmax between culprit and adjacent non-culprit segments was observed in patients with transient blood flow interruption during thermography (0.11+/-0.03 versus 0.08+/-0.01; P=0.04), in contrast to patients with preserved flow (0.07+/-0.03 versus 0.06+/-0.02; P=0.058).

CONCLUSIONS

The novel, technically sophisticated intracoronary thermography proved its safety and feasibility. However, we were not able to convincingly and consistently differentiate between different lesions at risk, despite a selection of lesions that should appear most distinct to differentiate. A systematic interruption of flow may be necessary to achieve diagnostic results consistently, although such requirement may unfavorably change the risk-to-benefit ratio of this developing technology.

Angiographic and clinical outcome after percutaneous coronary interventions following combined fibrinolytic therapy in acute myocardial infarction

INTRODUCTION

Combined therapy with fibrinolytic agent and platelet GPIIb/IIIa inhibitor not followed by an interventional procedure does not improve prognosis in patients presenting with acute ST-segment elevation myocardial infarction (STEMI) when compared to fibrinolysis alone. On the other hand, in the past percutaneous coronary interventions (PCI) performed after fibrinolysis were associated with low angiographic efficacy, a high risk of bleeding and a high rate of early cardiovascular events.

AIM

Evaluation of angiographic and clinical outcomes in patients with STEMI treated with PCI following combined fibrinolytic therapy.

METHODS AND RESULTS

Complete angiographic and clinical data of 187 patients who underwent PCI immediately after combined fibrinolytic therapy were obtained from a survey of 669 consecutive patients with STEMI <12 hours, at age <75 years, without cardiogenic shock, who were transferred from regional hospitals to the catheterisation laboratory within 90 minutes and after the initiation of combined fibrinolytic therapy (alteplase 15 mg iv as a bolus followed by an infusion of 35 mg over 60 minutes; abciximab iv bolus of 0.25 mg/kg followed by a 12 h infusion of 0.125 microg/kg per minute; unfractionated heparin). At baseline angiographic examination revealed no flow (TIMI 0+1) in the infarct-related artery in 17.1% of patients, impaired flow (TIMI 2) in 17.1% and normal (TIMI 3) in 65.8% of cases. After immediate PCI, a significant improvement in epicardial perfusion (TIMI 2+3, 99.5%) and in microcirculation was achieved. This favourable effect was seen only in the group of patients with baseline TIMI 0+1 flow, whereas PCI in the group with baseline TIMI 3 flow did not cause any further improvement in microcirculatory perfusion. The rate of cardiovascular events within the first 30 days and 12 months after the procedures were similar in the studied subgroup of patients.

CONCLUSIONS

PCI performed after combined fibrinolytic therapy in STEMI patients is associated with high efficacy and improvement in indices of epicardial perfusion and microcirculation. These benefits are confined mainly to patients with primarily impaired flow in the infarction-related artery (TIMI 0+1). However, the clinical results of this strategy, particularly in patients undergoing PCI following successful combined fibrinolytic therapy, must still be proved in further randomised trials.

Fractional flow reserve assessment to determine the indications for myocardial revascularisation in patients with borderline stenosis of the left main coronary artery

INTRODUCTION

Reliable assessment of clinical significance of borderline angiographic lesions found within the left main coronary artery (LM) is often impossible. Measurement of fractional flow reserve (FFR) is commonly used to verify borderline stenoses of the coronary arteries. However, the usefulness of FFR measurements has been validated only for arteries other than the LM.

AIM

Evaluation of the measured FFR value in determination of the indications for myocardial revascularisation in borderline LM stenosis.

METHODS

The study involved 38 patients aged 55+/-9 years (range 41-74 years) with isolated borderline LM stenosis. Each patient had the measurement of FFR performed during intravenous adenosine infusion at a dose of 140 microg/kg/min. Patients were referred for revascularisation if FFR was <0.75.

RESULTS

The mean LM stenosis in quantitative coronary angiography (QCA) was 45+/-10%. FFR<0.75 was found in 18 (47%) patients, whereas 20 (53%) subjects had FFR < or =0.75. In subjects with FFR <0.75 QCA showed significantly lower minimal lumen diameters (MLD) at the site of stenosis (1.84+/-0.45 vs 2.24+/-0.49, p=0.014). Additionally, a significant correlation was found between FFR and MLD (r=0.59, p<0.001). The mean clinical follow-up was 2 years (range 1-3 years). There were two (11%) fatal events in patients with FFR < or =0.75 who underwent CABG. One (5%) patient with FFR >0.75 underwent elective CABG due to progression of LMN stenosis. Moreover, one (5%) patient experienced myocardial infarction not related to borderline stenosis of the LM.

CONCLUSIONS

The measurement of FFR confirms the clinical significance of stenosis only in half of the patients with borderline isolated lesion of the left main coronary artery. Withdrawal from intervention in patients with FFR > or =0.75 is safe and is associated with favourable clinical outcomes in two-year follow-up.

[Long term follow-up after intracoranary brachytherapy due to in stent restenosis]

BACKGROUND

Intarcoronary brachytherapy with radioactive source is the method of choice to treat in stent restenosis. Currently, we have data available from randomized clinical trials, yet every day practice and routine results of barchytherapy are not completely defined.

METHODS

We studied 50 patients treated due to in stent restenosis. Procedures were performed by means of beta radiation, and the delivered dose was equal to 2000 cGy.

RESULTS

All patient were observed during hospitalization and long term follow-up (from 4 to 21 months). Diffuse and proliferative in stent restenosis (22.02 +/- 21.41 mm) was the most common type of lesions which were treated. Procedure success was 100%, and barchytherapy success was 98%. Median time of hospitalization was one day. Frequency of geographical miss was 7.8%. During in hospital period there were no cases of death, myocardial infarction nor need for revascularization. In long term follow-up 2 myocardial infarctions (4%), 1 bypass grafting (2%) and 9 target vessel revascularizations took place. The cumulative survival without event was 76%. Long term follow-up showed that adverse events occurred in the later period of observation, i.e., up to 6 months after brachytherpy. Median event free survival was 246.5 days.

CONCLUSIONS

Routine intracoronary brachytherapy due to in stent restenosis is safe and characterized by a high percentage of procedure success in long term follow-up.

Primary coronary angioplasty in patients with ST segment elevation acute myocardial infarction and diabetes

BACKGROUND

Subjects with diabetes constitute 13-25% of patients with ST segment elevation acute myocardial infarction (STEMI). In spite of the introduction of thrombolytic therapy, patients with STEMI and diabetes continue to have worse prognosis than those without diabetes. Primary percutaneous coronary intervention (PCI) has been shown in recent years to be the most effective therapy in patients with STEMI.

AIM

To compare the outcome of STEMI patients with or without diabetes who underwent primary PCI.

METHODS

The study group consisted of 500 consecutive patients with STEMI. The occurrence of major adverse cardiac events (MACE) which included death, reinfarction or repeated PCI of the target vessel, was analysed peri-operatively and during a six-month follow-up period.Results. Diabetes was diagnosed in 68 (13.6%) patients. The mean time duration from the onset of STEMI symptoms to treatment was similar in patients with or without diabetes (230+/-97 min vs 231+/-139 min, NS). Patients with diabetes were older (61.9+/-8.9 vs 57.9+/-10.8 years, p=0.004), had higher body mass index (29+/-4 vs 27+/-5, p=0.002), more frequent history of coronary artery disease (57.4% vs 37.9%, p=0.002), higher prevalence of arterial hypertension (71.6% vs 56.8%, p=0.02) and more frequently the left anterior descending artery as the infarct-related artery (58.8% vs 42.1%, p=0.01). Immediately after PCI, epicardial and myocardial reperfusion rates were lower in patients with rather than without diabetes (TIMI 3: 84.9% vs 91.3%, p=NS, cTFC: 32+/-26 vs 22+/-16, p<0.0001, and MPG3: 25% vs 41.9% p=0.008). Diabetes increased the risk of MACE during in-hospital period by 2.7 times. The rate of MACE during a six-month follow-up period was almost two times higher in patients with rather than without diabetes (death: 8.8% vs 5.1%, reinfarction: 1.5% vs 1.2%, repeated PCI: 11.8% vs 6.9%).

CONCLUSIONS

Primary PCI-achieved epicardial and myocardial reperfusion rate is lower in STEMI patients with rather than without diabetes. The presence of diabetes almost doubles the risk of MACE during a six-month follow-up.

[Assessment of myocardial reperfusion in patients with acute myocardial infarction treated with combination of fibrinolysis and IIb/IIIa platelet inhibitor]

Facilitated percutaneous coronary intervention (facilitated PCI) in acute myocardial infarction--the use of planned PCI after pharmacological reperfusion therapy, can fuse the best aspects of thrombolysis and primary angioplasty. The aim of the study was to assess microvacular reperfusion in patients with acute myocardial infarction treated with half dose of alteplase and full dose of abciximab followed by primary PCI.

METHODS

The study enrolled 100 patients with myocardial infarction within 12 hrs of chest pain onset in hospitals with at least 90 minutes of transportation time to interventional center. All patients received intravenous boluses of 60 U/kg heparin, 15 mg alteplase (r-tPA) and 0.25 mg/kg abciximab, and then infusions of: alteplase (35 mg/60 min) and abciximab (0.125 micrograms/kg/min for 12 hours) before transportation to interventional facility

RESULTS

Coronary angiography was performed at a mean 123 +/- 38 minutes after lytic therapy administration. In baseline angiography 73% of patients had TIMI 3 flow in infarct related artery. In 88 patients (90%) there was TIMI 2 + 3 flow. In 82 patients PCI was performed immediately after diagnostic catheterization, with angiographic procedural success rate of 92% (TIMI 3). Corrected TIMI frame count was 29.8 +/- 25.9 before and 17.2 +/- 9.5 after PCI. TIMI Myocardial Perfusion Grade 3 and 2 (MPG 3 + 2) was present in 77% of patients before and in 72% after PCI.

CONCLUSIONS

Combination of abciximab and half dose of alteplase was a very effective strategy in restoring flow in infarct related artery and achieving microvascular reperfusion. This model of pharmacological treatment could be utilized as pre-treatment for patients referred for primary PCI from remote hospitals.