Factors determining the frequency of optical coherence tomography and intravascular ultrasound use in patients treated with percutaneous coronary interventions in recent years: Analysis based on a large national registry

BACKGROUND

Intravascular ultrasound (IVUS) and optical coherence tomography (OCT) have demonstrated improvement in the clinical outcome of patients undergoing percutaneous coronary intervention (PCI).

AIMS

We aimed to examine the frequency of implementing OCT and IVUS during coronary angiography (CA) and PCI in everyday practice in Poland. Factors related to the more common choice of these imaging techniques were determined.

METHODS

Data from the Polish National Registry of Percutaneous Coronary Interventions (ORPKI) were procured for analysis. Between January 2014 and December 2021, we extracted data on 1 452 135 CAs, 11 710 using IVUS (0.8%) and 1471 with OCT (0.1%) and 838 297 PCIs, 15 436 with IVUS (1.8%) and 1680 with OCT (0.2%). We assessed the determining factors for applying IVUS and OCT via multiple regression logistics models.

RESULTS

The frequency of applying IVUS during CAs and PCIs increased significantly between the years 2014 and 2021. In 2021, it reached 1.54% for CAs and 4.42% for PCIs, while for OCT, there was a rise regarding the CA group, namely 0.13% in 2021, and, in the PCI group, 0.43%. Age was one of the factors significantly associated with the frequency of using IVUS/OCT during CA/PCI, which was confirmed by multivariate analysis (Odds ratio: 0.981 for IVUS and 0.973 for OCT use with PCI).

CONCLUSION

The frequency at which IVUS and OCT were used has undergone a significant increase in previous years. This increase can be largely attributed to the current reimbursement policies. Further improvement is required for this frequency to be at a satisfactory level.

Presence of retained calcified fibrin sheath after central venous catheter removal: A systematic literature review

Central venous catheters (CVC) are used in many clinical settings for a variety of indications. We performed a systematic literature review concerning case reports of retained calcified fibrin sheaths after dialysis CVC removal. The aim of our study was to systematize the knowledge regarding clinical management of this phenomenon, placing special emphasis on diagnostic radiological features in different imaging modalities, including chest radiography, echocardiography, computed tomography, and magnetic resonance imaging. We discuss the most common risk factors associated with this CVC complication. In our review, we found eight cases of hemodialysis patients. The most common risk factors associated with calcified fibrin sheath formation in the analyzed cases were pro-thrombotic and pro-calcification factors related to patient comorbidities, and prolonged catheter dwell time. Differentiating between a calcified fibrin sheath (present in about 6% of patients with long-term indwelling CVC as diagnosed by computed tomography) and a retained catheter tip can be challenging. The initial diagnosis based on imaging methods was incorrect in most of the analyzed cases. This suggests that some cases of retained fibrin sheaths may remain undetected or misinterpreted. This is important in patients with known pro-thrombotic and pro-calcification risk factors and prolonged catheter dwell time. Therefore, implementation of preventive strategies, familiarity with radiological findings of this phenomenon, comparison with previous imaging studies, and an overall comprehensive assessment with clinical data is imperative.

Design and rationale for the Myocardial Stem Cell Administration After Acute Myocardial Infarction (MYSTAR) Study: a multicenter, prospective, randomized, single-blind trial comparing early and late intracoronary or combined (percutaneous intramyocardial and intracoronary) administration of nonselected autologous bone marrow cells to patients after acute myocardial infarction

BACKGROUND

Previous data suggest that bone marrow-derived stem cells (BM-SCs) decrease the infarct size and beneficially affect the postinfarction remodeling.

METHODS

The Myocardial Stem Cell Administration After Acute Myocardial Infarction Study is a multicenter, prospective, randomized, single-blind clinical trial designed to compare the early and late intracoronary or combined (percutaneous intramyocardial and intracoronary) administration of BM-SCs to patients after acute myocardial infarction (AMI) with reopened infarct-related artery. The primary end points are the changes in resting myocardial perfusion defect size and left ventricular ejection fraction (gated single photon emission computed tomography [SPECT] scintigraphy) 3 months after BM-SCs therapy. The secondary end points relate to evaluation of (1) the safety and feasibility of the application modes, (2) the changes in left ventricular wall motion score index (transthoracic echocardiography), (3) myocardial voltage and segmental wall motion (NOGA mapping), (4) left ventricular end-diastolic and end-systolic volumes (contrast ventriculography), and (5) the clinical symptoms (Canadian Cardiovascular Society [CCS] anina score and New York Heart Association [NYHA] functional class) at follow-up. Three hundred sixty patients are randomly assigned into 1 of 4 groups: group A, early treatment (21-42 days after AMI) with intracoronary injection; group B, early treatment with combined application; group C, late treatment (3 months after AMI) with intracoronary delivery; and group D, late treatment with combined administration of BM-SCs. Besides the BM-SCs therapy, the standardized treatment of AMI is applied in all patients.

CONCLUSIONS

The Myocardial Stem Cell Administration After Acute Myocardial Infarction Trial is the first randomized trial to investigate the effects of the combined (intramyocardial and intracoronary) and the intracoronary mode of delivery of BM-SCs therapy in the early and late periods after AMI.

Stenting of unprotected left main coronary artery in patients with low preoperative risk of coronary artery bypass grafting

INTRODUCTION

Available data indicate that stenting of the left main coronary artery (LMN) is safe and effective. Restenosis remains the main factor limiting the effectiveness of percutaneous coronary intervention (PCI).

AIM

To evaluate immediate and long-term results of treatment of patients with LMN disease and low preoperative risk of coronary artery bypass grafting.

METHODS

Coronary stents were implanted into LMN in 64 patients. The following strategy was applied: drug eluting stent (DES) for LMN diameter < or =3.5 mm (28 subjects) and bare metal stent (BMS) for LMN diameter >3.5 mm (36 subjects). Patients enrolled in the study underwent clinical evaluation and coronary angiography. Immediate effect of the procedure and main adverse cardiac events were assessed: death, myocardial infarction and additional target lesion or non-target lesion revascularization.

RESULTS

Angiographic and clinical effectiveness of the interventions was 100%. Full revascularisation of ischaemic regions of the myocardium was performed. Mean clinical follow-up period was 9.4+/-4.0 months. Neither death nor myocardial infarction occurred. Additional PCIs were performed in 11 (17.2%) patients; however, target vessel revascularisation (TVR) rate within LMN was 9.4% (i.e. 6 subjects with BMS), and non-TVR rate was 7.8% (5 subjects).

CONCLUSIONS

LMN stenting is associated with high effectiveness of PCI in patients with low operative risk. Long-term follow-up revealed low incidence of major adverse cardiac events. Strategy of selective use of DESs in the study group produced good clinical outcome. Multivessel disease with LMN stenosis was associated with high rate of additional revascularisation of other vessels. Further improvement of treatment results may be obtained by more common use of DES for multivessel disease and LMN diameters larger than 4.0 mm.

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.

Effect of early statin and selective cyclooxygenase-2 inhibitor therapy on C-reactive protein level after percutaneous coronary angioplasty in unstable angina

AIMS

We evaluated the effect of cyclooxygenase-2 inhibitor rofecoxib added to atorvastatin, initiated immediately after percutaneous coronary angioplasty (PCI), on C-reactive protein (CRP) and interleukin-6 (IL-6) in patients with unstable angina (UA).

METHODS AND RESULTS

Sixty patients were prospectively randomized to receive: (A) 10 mg atorvastatin or (B) 40mg atorvastatin or (C) atorvastatin 40 mg plus rofecoxib 12.5 mg. Treatment was continued for 6 months. CRP and IL-6 levels increased within 48 hours after PCI in all groups, in comparison with A and B, a more pronounced decrease in CRP (mg/l) and IL-6 (pg/ml) levels at 3- and 6-month follow-up was present in C: CRP at 6 months: 0.76 vs. 1.92 vs. 0.11, p<0.05; IL-6 at 6 months: 0.02 vs. 0.04 vs. 0.01, p<0.05. At 6-month follow-up the reduction in CRP level occurred in 70% of subjects with CRP higher than median (3.6mg/l) at baseline vs. 15% of patients with CRP lower than median (p<0.041).

CONCLUSION

After PCI in UA, cyclooxygenase-2 inhibitor rofecoxib added to atorvastatin reduced CRP and IL-6 levels more profoundly than atorvastatin alone at 3- and 6-month after intervention. In the group receiving combined therapy, reduction in CRP levels was more frequently observed in patients with higher CRP at baseline.

Inter-individual variability in response to clopidogrel in patients with coronary artery disease

BACKGROUND

Clopidogrel, especially when combined with aspirin, reduces the rate of ischaemic events in patients with coronary artery disease (CAD). There are scare data in literature on the inter-individual variability in response to clopidogrel.

AIM

To assess the incidence of clopidogrel resistance using rapid whole blood platelet function assessment, and to examine the possibility of early identification of non-responders.

METHODS

In 31 consecutive patients with stable angina treated with aspirin, the degree of platelet aggregation inhibition (DPAI) in the whole blood was assessed at baseline and 3, 6, 12 as well as 24 hours after administration of loading dose of clopidogrel (300 mg). Response to clopidogrel was measured by calculating the absolute difference between the baseline DPAI and DPAI obtained at the investigated time-points (DPAI).

RESULTS

After 24 hours from clopidogrel administration, seven (22.6%) patients were identified as non-responders (DPAI < or =10%). Demographic and clinical variables as well as baseline DPAI were similar in responders and non-responders (DPAI: 5.8+/-3.7% vs 7.1+/-5.3%, p=NS). Out of the patients who were found to be resistant to clopidogrel at the six-hour time-point, 87.5% remained resistant to this agent 24 hours after drug administration. DPAI calculated at the 24-hour time-point highly correlated with the six-hour DPAI (r=0.74). No differences in the rate of ischaemic or bleeding complications between responders and non-responders were noted.

CONCLUSIONS

The assessment of the degree of platelet aggregation inhibition allows early (six hours from the initiation of treatment) identification of patients who are resistant to clopidogrel. The method of the rapid whole blood platelet function assessment is feasible in every-day clinical practice.

[Safety and effectiveness of pharmacologic versus mechanical stabilization of borderline coronary lesions in patients with acute coronary syndromes]

INTRODUCTION

Borderline coronary lesions are responsible for about 80% of acute coronary syndromes (ACS). Statins have been found to improve long-term prognosis in patients with coronary artery disease due to plaque stabilization. There are no reports on the frequency of new events caused by progression of borderline lesions in patients with (ACS). Percutaneous coronary intervention (PCI) as a method of mechanical stabilization of borderline coronary lesions could be an alternative to pharmacological approach.

AIM

To compare the efficacy of pharmacological and mechanical stabilization of borderline plaques (DS = 40-60%) in patients with ACS.

PATIENTS AND METHODS

Patients with ACS and angiographically documented borderline lesions, related to the ACS or located in other coronary arteries were enrolled. Patients were randomized to receive pharmacotherapy without intervention or to undergo PCI. The primary end-point was rate of target lesion revascularization with PCI or coronary bypass grafting (CABG) caused by progression of coronary stenosis or in-stent restenosis/thrombosis. The secondary endpoint was incidence of major adverse cardiac events (MACE) at long-term follow-up (death, ST segment elevation acute coronary syndrome--STEACS and non-ST segment elevation acute coronary syndrome-- NSTEACS).

RESULTS

Pharmacological stabilization was used in 50 patients, mean age 56.7 +/- 9.14 years, whereas 44 patients, mean age 57.2 +/- 10.4 years, underwent plaque stabilization with PCI. At follow-up (mean 521 days) target lesion revascularization was performed in 3 patients, previously receiving pharmacotherapy, due to progression of coronary stenosis, and in 3 patients, after prior PCI, due to in-stent restenosis (7% vs. 8%, p = NS). The rate of MACE in both groups was also similar (6% vs. 5%, p = NS).

CONCLUSION

There were no differences between mechanical and pharmacological stabilization of borderline coronary lesions in patients with acute coronary syndromes.

[The effects of intracoronary brachytherapy on long-term patency of previously chronically occluded bypass graft--a case report]

A case of a 70-year-old female who underwent CABG (four grafts) 12 years earlier, is presented. Following surgery, the patient suffered from two reinfarctions. Coronary angiography revealed total occlusion of the graft implanted to the right coronary artery which was treated by coronary angioplasty. Because of restenosis, the patient underwent successful intracoronary brachytherapy.

[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.

High-dose statin and COX-2 inhibitor therapy rapidly decreases C-reactive protein level in patients with unstable angina

BACKGROUND AND AIM

Elevated levels of C-reactive protein (CRP) are associated with an increased risk of coronary events. The levels of CRP and other inflammatory markers are significantly elevated in patients with unstable angina. We hypothesised that a high-dose statin therapy alone or with cyclooxygenase-2 (COX-2) inhibitors, administered before coronary diagnostic or invasive procedures, can attenuate CRP elevation after the procedure and, consequently, more effectively reduce the rate of coronary events.

METHODS

All patients with unstable angina in class III and IIB according to Braunwald classification were considered for inclusion in the present study. Finally, 60 patients with elevated CRP level (>3 mg/l) were randomised to three groups of pharmacological treatment before coronary angiography and subsequent angioplasty. Patients from group A received placebo, patients from group B - 80 mg of atorvastatin, and patients from group C - 80 mg of atorvastatin and 25 mg of rofecoxib. The levels of CRP were measured at baseline, after 3 days of therapy and 48 hours after invasive coronary procedure.

RESULTS

The mean baseline CRP level in group A was 5.67+/-2.82 mg/l, in group B - 4.7+/-1.32 mg/l, and in group C - 6.78+/-2.56 mg/l (NS). After three days of pharmacological treatment, the mean CRP level was 5.82+/-2.69 mg/l in group A (NS compared with baseline) and was significantly reduced in group B to 2.5+/-1.37 mg/l and in group C to 3.01+/-1.57 mg/l (p<0.0013 compared with group A). Measurements performed 48 hours after the procedure revealed a marked CRP level increase in group A (up to 24.54+/-5.48 mg/l) and a much lower increase in groups B and C (up to 3.02+/-2.0 mg/l and 7.31+/-2.96 mg/l, respectively).

CONCLUSIONS

High-dose statin therapy alone or in combination with COX-2 inhibitor, administered before invasive coronary procedure in patients with unstable angina, rapidly lowers CRP levels. This therapy also reduces a marked CRP elevation typically occurring after invasive coronary intervention. Attenuation of inflammatory reaction may be crucial for the reduction of coronary events following invasive coronary interventions.

L-arginine supplementation does not inhibit neointimal formation after coronary stenting in human beings: an intravascular ultrasound study

BACKGROUND

In-stent restenosis results from neointimal tissue proliferation. L-arginine supplementation improves endothelial function and reduces neointimal formation after arterial injury in animals. The aim of the study was to assess the influence of L-arginine administration on neointimal proliferation after coronary stenting in human beings.

METHODS

We performed a prospective, randomized, double-blinded, placebo-controlled study in 60 men without diabetes. L-arginine/placebo was administered intravenously 12 hours before percutaneous coronary intervention (200 mg/kg for 240 minutes), during the procedure (200 mg/kg for 240 minutes), and intracoronarily immediately before stent implantation (500 mg for 10 minutes), and it was followed by oral treatment for next 2 weeks (6.0 g/d). By quantitative coronary angiography, late lumen loss, and intravascular ultrasound, neointimal volume and percent neointimal volume were calculated after 7 months of follow-up to assess neointimal formation.

RESULTS

There were no differences in baseline clinical or angiographic characteristics between the two groups. Intravenous infusion of L-arginine increased plasma L-arginine concentrations 6-fold compared with placebo (661 +/- 264 vs 107 +/- 71 mmol/L, P <.001). During the 2-week period of oral treatment with L-arginine there was a sustained, significant increase of plasma L-arginine level (150 +/- 50 vs 100 +/- 17, P <.001, 135 +/- 42 vs 89 +/- 27, P <.001, respectively, on days 7 and 14 in the L-arginine group vs placebo). However, at 7-month follow-up, there was no difference in neointimal formation measured both by quantitative coronary angiography and intravascular ultrasound between the study groups.

CONCLUSIONS

Chronic systemic L-arginine administration has no effect on neointimal formation after coronary stenting in human beings.

Transthoracic, harmonic mode, contrast enhanced color Doppler echocardiography in detection of restenosis after percutaneous coronary interventions. Prospective evaluation verified by coronary angiography

AIMS

To test the feasibility and accuracy of transthoracic, harmonic mode, contrast enhanced Doppler echocardiographic assessment of lesion severity after PCI treatment in native coronary arteries--the LAD, Cx and RCA.

METHODS AND RESULTS

Prospective evaluation of 59 patients (66 arteries). Restenosis was diagnosed whenever maximal flow velocity at least doubled in comparison to the segment immediately proximal to the PCI site or when local velocity was at least 2 m/s. At 9 months of follow-up final comparison of Doppler echocardiography and coronary angiography was performed with regard to 44 arteries in 40 patients. Of LAD segments assessed, 15 were proximal and 15 middle. The figures for Cx segments were: 4 proximal and 2 mid, and for RCA 2 proximal, 5 middle and 1 distal (i.e. the posterior descending coronary artery). On final coronary angiography there were 8 restenoses--all correctly diagnosed by echocardiography. There were 2 false-positive diagnoses of restenosis. Specificity for restenosis detection was 94% and sensitivity 100%.

CONCLUSION

Transthoracic echocardiography allowed for accurate stenosis assessment of principal coronary arteries after successful PTCA. Feasibility of lesion site visualization was 100% for the LAD, 75% for the Cx and 43% for the RCA. Ultrasound contrast agent improved the quality of the RCA images.

[Primary percutaneous coronary interventions in acute myocardial infraction with ST-segment elevation. Experience in a heart catheterization unit without surgical backup]

BACKGROUND

Primary percutaneous coronary intervention (PCI) in patients (pts) with ST-segment elevation myocardial infarction is regarded as treatment superior to thrombolysis. Coronary stents and GP IIb/IIIa receptor inhibitors improved safety and clinical outcome of interventional procedures. Safety of primary PCI procedure in catheterisation laboratories which do not have on-site surgical backup is still under evaluation.

METHODS

In a cohort of 249 consecutive patients we analysed short and long-term clinical outcome of primary PCI performed in catheterisation laboratory which is located several kilometres from a cardiac surgery department, with an effective transfer time < 30 minutes.

RESULTS

Coronary stents were implanted in 43% pts. GP IIb/IIIa receptor inhibitors were used in 54.2% pts. Cardiogenic shock on admission was diagnosed in 7.2% pts. Intra-aortic balloon counterpulsation usage was necessary in 6.4% pts. In-hospital mortality was 6% (3.5% in non-shock pts). In two pts (0.8%) during hospitalization repeat PCI was performed--in one case due to reinfarction. No urgent cardiosurgery intervention was necessary. Mortality and myocardial infarction rate after hospital discharge during 6 month follow up was 2.4% and 2.8% respectively. In 4% pts repeated PCI was performed due to restensosis. Cumulative event free survival was 84%.

CONCLUSION

Primary PCI procedure for acute myocardial infarction seems to be feasible and safe in catheterisation laboratories without on-site surgical backup provided usage of stents, GPIIb/IIIa receptor inhibitors and intraaortic balloon counterpulsation and cooperation with a nearby cardiosurgery department with short transfer time.

Effects of L-arginine supplementation on endothelial function after stent implantation

BACKGROUND

In-stent restenosis after percutaneous coronary intervention (PCI) is due to the proliferation of intima. Supplementation with L-arginine has been shown to improve endothelial function and decrease neointima proliferation in experimental animal model of restenosis.

AIM

To assess the effects of L-arginine supplementation on neointima proliferation and endothelial markers as well as growth factor levels in patients after stent implantation.

METHODS

In this prospective, randomised, double-blind, placebo-controlled study 60 patients undergoing stent implantation received placebo or L-arginine (200 mg/kg infused intravenously over 4 hours, 12 and 3 hours before PCI, and 500 mg over 10 minutes prior to stent implantation, followed by oral supplementation of 6 g/day for 14 days after PCI). Quantitative coronary angiography (QCA) and intracoronary ultrasonography (ICUS) were performed at baseline and after a seven-month follow-up period. Serum concentration of L-arginine was measured at baseline, before PCI, 24 hours after PCI, and 7 as well as 14 days after PCI. The transforming growth factor-beta (TGF-beta), vascular endothelial growth factor (VEGF) and endothelin levels were assessed before PCI, and 24 hours as well as 14 days after the procedure.

RESULTS

No significant differences in the QCA or ICUS parameters were found between patients receiving L-arginine or placebo. 24 hours after stent implantation patients who received placebo had significantly a higher increase in the endothelin serum concentration and a lower rise in the VEGF level than the patients who received L-arginine (92.6+/-49 pg/ml vs 76.1+/-27 pg/ml, p<0.05, and 10 pg/ml vs 17.6+/-12 pg/ml, p<0.05, respectively). The TGF-beta level, assessed 14 days after PCI, was significantly higher in the placebo group than in the L-arginine group (14.8+/-10 ng/ml vs 11.2+/-6.1 ng/ml, p<0.05).

CONCLUSIONS

In spite of favourable changes in the vascular endothelial biochemical marker profile, supplementation with L-arginine did not decrease the in-stent reocclusion rate.

[Therapeutic angiogenesis for coronary artery disease. Contemporary results and perspectives]

Therapeutic angiogenesis is referred to as development of new vasculature caused by various therapeutic measures such as: gene therapy, growth factors, percutaneous and transmyocardial laser revascularization. The scope of the current article is to provide review of performed clinical trials using therapeutic angiogenesis in patients with coronary artery disease.

The time course of tumor necrosis factor-alpha, inducible nitric oxide synthase and vascular endothelial growth factor expression in an experimental model of chronic myocardial infarction in rats

An injury to the heart due to myocardial infarction may progress to heart failure. Among the cytokines and growth factors whose interactions promote remodeling of the heart, increased expression of tumor necrosis factor (TNF)-alpha, inducible nitric oxide synthase (iNOS) and vascular endothelial growth factor (VEGF) has been found. However, little is known about the sequence of gene expression during the progression of heart injury. In the present study, male Sprague-Dawley rats were used for experimental myocardial infarction performed by ligation of the left anterior descending coronary artery. TNF-alpha, iNOS and VEGF expression was assessed by reverse transcription polymerase chain reaction. Localization of TNF-alpha, VEGF and iNOS protein was assessed by immunohistochemistry. An in vitro proliferation (BrdU incorporation) and differentiation (tube formation) assay of human umbilical vein endothelial cells was performed. The expression of TNF-alpha, iNOS, VEGF(164) and VEGF(188) was observed during the whole period after myocardial infarction (on days 1, 4, 11, 28 and 40), whereas VEGF(120) was found only on day 1 and 4. The most intense immunostaining for TNF-alpha was observed at the border zone. The iNOS immunostaining was initially located in the endothelium, whereas later it was also present in the walls of larger vessels. The VEGF protein was present in the border zone. No gene expression or immunostaining was detected in sham-operated rats. The in vitro experiments showed both proangiogenic (low TNF-alpha concentration, short period of incubation) and antiangiogenic (high TNF-alpha concentration, long period of incubation) effects of TNF-alpha. The expression of TNF-alpha and iNOS genes with the concomitant occurrence of a decrease in VEGF(120), VEGF(188) and VEGF(164) protein could be related to insufficient angiogenesis and may suggest the possible involvement of these events in remodeling after myocardial infarction.

Relation between expression of TNF alpha, iNOS, VEGF mRNA and development of heart failure after experimental myocardial infarction in rats

An injury to the heart due to myocardial infarction (MI) may progress to heart failure. Among factors, whose interactions promote remodeling of ischemic myocardium, the increased expression of tumor necrosis factor alpha (TNFalpha), inducible nitric oxide synthase (iNOS) and Vascular Endothelial Growth Factor (VEGF) was found. However, little is known about the temporal and spatial relation between expression of iNOS, cytokine TNFalpha, and growth factor VEGF during pathological process of development of heart failure after the myocardial infarction. Male Sprague-Dawley rats were used for experimental myocardial infarction. The procedure was performed by anterolateral thoracotomy and snearing LAD with the metal clip. The hemodynamic measurements were done with the Langendorff preparation converted into a working heart system. The hemodynamic parameters were recorded at day 6, 11, 28, 40 and the myocardium for gene expression was collected at day 1, 4, 11, 28, 40. Control group was sham operated rats. The VEGF, TNFalpha, iNOS, and GAPDH genes were detected by RT-PCR assay from samples taken at border zone of myocardial infarction. Expression of isoform VEGF120 was found at day 1 and 4 after MI, whereas isoforms VEGF164 and VEGF188 along with expression of TNFalpha and iNOS was found at day 1, 4, 11, 28, 40. No expression of examined genes was detected in the myocardium of control rats. The expression of studied factors was parallel with development of heart failure after myocardial infarction assessed by hemodynamic measurements. These findings confirm the postulated involvement of TNFalpha, iNOS and growth factor VEGF in the remodeling of the myocardium and development of heart failure after experimental myocardial infarction.