Balloon deflection technique: A method to facilitate entry of a balloon catheter into a deployed stent

The entry of an angioplasty balloon into a coronary stent is occasionally difficult due to poorly expanded stent struts or calcified tissue blocking balloon passage. We describe a simple technique using a second guidewire and balloon to facilitate entry into the stent. Cathet. Cardiovasc. Intervent. 51:312-313, 2000.

Combination of a direct thrombin inhibitor and a platelet glycoprotein IIb/IIIa blocking peptide facilitates and maintains reperfusion of platelet-rich thrombus with alteplase

We sought to determine the efficacy of the combination of argatroban, a direct thrombin inhibitor, and G4120, a platelet glycoprotein (GP) IIb/IIIa blocker, to enhance thrombolysis with alteplase. Platelet-rich thrombus in the rabbit arterial thrombosis model is relatively resistant to alteplase despite the addition of aspirin and heparin. The adjunctive use of either direct thrombin inhibitors or GP IIb/IIIa inhibitors in thrombolysis has been investigated with encouraging, but limited, success. The usefulness of combining both agents as adjunctive therapy to thrombolysis has not been fully explored. Following platelet-rich thrombus formation in the rabbit, argatroban (3 mg/kg), G4120 (0.5 mg/kg), G4120 plus heparin (200 U/kg), or G4120 plus argatroban were intravenously infused over 60 minutes. Alteplase was given as intravenous boluses (0.45 mg/kg) at 15-minute intervals up to 4 doses or until reperfusion. Blood flow and bleeding time were monitored for 2 hours. The combination of G4120 plus argatroban resulted in a persistent patency in 5 of 7 animals compared with 0 of 6 for argatroban alone (p=0.02), 1 of 6 for G4120 alone (p=0.08), and 2 of 6 for G4120 plus heparin (p=0.2). Although during the infusion the bleeding times were longer in the groups that received G4120 (26+/-7.7 minutes vs. 14+/-10 minutes, p<0.05), by the end of the experiment there were no statistically significant differences. Similarly, during the infusion the activated partial thromboplastin times (aPTT) was higher in groups that received heparin or argatroban (99+/-51 seconds vs. 32+/-7.6 seconds, p<0.001), but by the end of the experiment the aPTTs had returned to close to baseline in all groups except the G4120 plus heparin group. These results suggest that lysis of platelet-rich thrombus with alteplase requires the addition of both potent platelet and thrombin inhibitors. Specifically designed agents, G4120 and argatroban, are effective without additional increased risk for bleeding.

Effects of tirofiban plus heparin versus heparin alone on troponin I levels in patients with acute coronary syndromes

Elevated serum troponins following an acute coronary syndrome (ACS) predict a poor clinical outcome. Glycoprotein (GP) IIb/IIIa inhibitors reduce adverse clinical outcomes in patients with ACS, although their effect on serum troponin I (TnI) in this setting has not been described. We therefore studied the effects of the GP IIb/IIIa inhibitor tirofiban on serum TnI levels in a group of patients in the Platelet Inhibition in Ischemic Syndrome Management in Patients Limited by Unstable Signs and Symptoms trial. Serial blood samples were obtained in 53 patients receiving the combination therapy of tirofiban/heparin and in 52 receiving heparin alone, and were analyzed for baseline, peak, and mean concentrations of TnI. Baseline TnI levels were not different between the combination therapy and heparin-only groups (1.6 +/- 3.0 vs 3.1 +/- 6.7 ng/ml, p = 0.15). The peak TnI level was significantly lower in the combination therapy group than in the heparin group (5.2 +/- 8.3 vs 15.5 +/- 29.1 ng/ml, p = 0.017), and mean levels over the initial 24-hour period were also significantly lower in the combination therapy group (3.2 +/- 5.0 vs 8.5 +/- 14.8 ng/ml, p = 0.016). In univariate analysis, combination therapy was associated with lower TnI levels, whereas in a multivariate model, the lower peak and mean TnI levels as a consequence of tirofiban/heparin compared with heparin monotherapy remained significant (peak, p = 0.029; mean, p = 0.035). Among patients with negative TnI at baseline, treatment with the combination of tirofiban/heparin compared with heparin monotherapy still resulted in significantly lower peak (2.5 +/- 5.4 vs 14.6 +/- 32.8 ng/ml, p = 0.024) and mean (1.2 +/- 2.6 vs 6.9 +/- 15.8 ng/ml, p = 0.029) TnI levels. In patients with ACS, therapy with the combination of tirofiban and heparin (compared with heparin treatment alone) resulted in lower serum TnI levels, suggesting reduced myocardial injury.

Prevalence of early left ventricular thrombus after primary coronary intervention for acute myocardial infarction

The prevalence of left ventricular (LV) thrombus after acute myocardial infarction (AMI) has been reported high at 20-60%. Current reperfusion therapies such as thrombolysis have shown a trend toward reducing the incidence of LV thrombosis. However, the prevalence of LV thrombus after primary percutaneous coronary intervention (PCI) for AMI has not been systematically studied. At Massachusetts General Hospital 71 consecutive patients who underwent primary PCI for acute ST elevation MI were reviewed for the prevalence of LV thrombus evaluated by echocardiography. Echocardiography was performed within 5 days of infarction. PCI was successful in all patients. The time delay from symptom onset to intervention was 191 minutes. Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was achieved in more than 80% of cases. Only 3 patients (4%) had echocardiographic evidence of LV thrombus. All 3 patients had anterior infarctions. The incidence among patients with anterior MI was 10% (3 of 30 patients). The prevalence of LV thrombus in patients treated with primary PCI for AMI is low (4%).

The use of glycoprotein IIb/IIIa inhibitors in patients with coronary artery disease

Platelet membrane glycoprotein IIb/IIIa inhibitors, a new class of potent antiplatelet agents, have been used in the treatment of acute coronary syndromes as well as in the prevention of complications after percutaneous coronary interventions. Approximately 50,000 patients with coronary artery disease have been enrolled in randomized studies of glycoprotein IIb/IIIa inhibitors. The purpose of this article is to review the pharmacology of glycoprotein IIb/IIIa inhibitors, the results of the clinical trials using these agents, and their current use in percutaneous coronary interventions and the treatment of acute coronary syndromes.

Porcine coronary imaging in vivo by optical coherence tomography

OBJECTIVE

A high-resolution coronary artery imaging modality has the potential to address important diagnostic and management problems in cardiology. Optical coherence tomography (OCT) is a promising new optical imaging technique with a resolution of approximately 10 microm. The purpose of this study was to use a new OCT catheter to demonstrate the feasibility of performing OCT imaging of normal coronary arteries, intimal dissections, and deployed stents in vivo.

METHODS AND RESULTS

Normal coronary arteries, intimal dissections, and stents were imaged in five swine with OCT and compared with intravascular ultrasound (IVUS). In the normal coronary arteries, visualization of all of the layers of the vessel wall was achieved with a saline flush, including the intima which was not identified by IVUS. Following dissection, detailed layered structures including intimal flaps, intimal defects, and disruption of the medial wall were visualized by OCT. IVUS failed to show clear evidence of intimal and medial disruption. Finally, the microanatomic relationships between stents and the vessel walls were clearly identified only by OCT.

CONCLUSIONS

In this preliminary experiment, we have demonstrated that in vivo OCT imaging of normal coronary arteries, intimal dissections, and deployed stents is feasible, and allows identification of clinically relevant coronary artery morphology with high-resolution and contrast.

Primary versus rescue percutaneous coronary intervention in patients with acute myocardial infarction

OBJECTIVE

To compare angiographic and clinical outcomes of patients with acute myocardial infarction (AMI) who underwent primary percutaneous coronary intervention (PCI) versus rescue PCI following failed thrombolysis.

BACKGROUND

Patients presenting with AMI are treated either with primary PCI or with thrombolysis. When thrombolysis fails, rescue PCI is performed.

METHODS AND RESULTS

We compared the outcome of 105 consecutive patients with AMI who underwent either primary PCI (60 patients) or rescue PCI (45 patients) between January 1997 and January 1999. The patients were followed for up to 6 months. Time delay to reperfusion was significantly longer in the rescue PCI group (354 vs. 189 min; p < 0.001). The majority of patients received a stent (93%). Glycoprotein (GP) IIb/IIIa inhibitors were used in 53% of patients in the primary PCI group and in 22% in the rescue group. TIMI grade 3 flow was achieved in 93.3% of patients in the primary PCI group and in 88.8% in the rescue group (p = 0.08). Post-procedure ejection fraction was 53% in the primary PCI group and 47% in the rescue group (p = 0.014). A composite endpoint of death, recurrent MI, repeat PCI, coronary artery bypass grafting (CABG) and recurrent angina at 6 months occurred in 35% of the patients in the primary PCI group and 26.7% in the rescue group (p = 0.36).

CONCLUSION

Despite a significant delay to reperfusion and a lower immediate post-procedure ejection fraction, the clinical outcome of patients treated with rescue PCI following failed thrombolysis appears to be similar to that of patients treated with primary PCI at 6 months.

Cbl-b regulates the CD28 dependence of T-cell activation

Whereas co-stimulation of the T-cell antigen receptor (TCR) and CD28 triggers T-cell activation, stimulation of the TCR alone may result in an anergic state or T-cell deletion, both possible mechanisms of tolerance induction. Here we show that T cells that are deficient in the adaptor molecule Cbl-b (ref. 3) do not require CD28 engagement for interleukin-2 production, and that the Cbl-b-null mutation (Cbl-b(-/-)) fully restores T-cell-dependent antibody responses in CD28-/- mice. The main TCR signalling pathways, such as tyrosine kinases Zap-70 and Lck, Ras/mitogen-activated kinases, phospholipase Cgamma-1 and Ca2+ mobilization, were not affected in Cbl-b(-/-) T cells. In contrast, the activation of Vav, a guanine nucleotide exchange factor for Rac1/Rho/CDC42, was significantly enhanced. Our findings indicate that Cbl-b may influence the CD28 dependence of T-cell activation by selectively suppressing TCR-mediated Vav activation. Mice deficient in Cbl-b are highly susceptible to experimental autoimmune encephalomyelitis, suggesting that the dysregulation of signalling pathways modulated by Cbl-b may also contribute to human autoimmune diseases such as multiple sclerosis.

Frequency of silent myocardial ischemia following coronary stenting

To detect silent myocardial ischemia, 12-lead continuous electrocardiographic monitoring was performed in patients undergoing 1-vessel coronary stenting. Despite successful angiographic results, one third of the patients experienced silent myocardial ischemia during the postprocedural period.

Heparin induced thrombocytopenia: diagnosis and contemporary antithrombin management

Heparin-induced thrombocytopenia (HIT) may be complicated by severe thrombotic complications and death. Currently no specific laboratory test is available to make the diagnosis. When HIT is clinically suspected, heparin should be discontinued immediately. While no specific therapy for HIT exists, there is increasing evidence that acute antithrombin therapy may significantly reduce morbidity and mortality. Among several agents, the direct antithrombins, such as r-hirudin and argatroban, look the most promising for acute treatment.

A multicenter, randomized study of argatroban versus heparin as adjunct to tissue plasminogen activator (TPA) in acute myocardial infarction: myocardial infarction with novastan and TPA (MINT) study

OBJECTIVES

This study examined the effect of a small-molecule, direct thrombin inhibitor, argatroban, on reperfusion induced by tissue plasminogen activator (TPA) in patients with acute myocardial infarction (AMI).

BACKGROUND

Thrombin plays a crucial role in thrombosis and thrombolysis. In vitro and in vivo studies have shown that argatroban has advantages over heparin for the inhibition of clot-bound thrombin and for the enhancement of thrombolysis with TPA.

METHODS

One hundred and twenty-five patients with AMI within 6 h were randomized to heparin, low-dose argatroban or high-dose argatroban in addition to TPA. The primary end point was the rate of thrombolysis in myocardial infarction (TIMI) grade 3 flow at 90 min.

RESULTS

TIMI grade 3 flow was achieved in 42.1% of heparin, 56.8% of low-dose argatroban (p = 0.20 vs. heparin) and 58.7% of high-dose argatroban patients (p = 0.13 vs. heparin). In patients presenting after 3 h, TIMI grade 3 flow was significantly more frequent in high-dose argatroban versus heparin patients: 57.1% versus 20.0% (p = 0.03 vs. heparin). Major bleeding was observed in 10.0% of heparin, and in 2.6% and 4.3% of low-dose and high-dose argatroban patients, respectively. The composite of death, recurrent myocardial infarction, cardiogenic shock or congestive heart failure, revascularization and recurrent ischemia at 30 days occurred in 37.5% of heparin, 32.0% of low-dose argatroban and 25.5% of high-dose argatroban patients (p = 0.23).

CONCLUSIONS

Argatroban, as compared with heparin, appears to enhance reperfusion with TPA in patients with AMI, particularly in those patients with delayed presentation. The incidences of major bleeding and adverse clinical outcome were lower in the patients receiving argatroban.

Identification of a novel activation-inducible protein of the tumor necrosis factor receptor superfamily and its ligand

Among members of the tumor necrosis factor receptor (TNFR) superfamily, 4-1BB, CD27, and glucocorticoid-induced tumor necrosis factor receptor family-related gene (GITR) share a striking homology in the cytoplasmic domain. Here we report the identification of a new member, activation-inducible TNFR family member (AITR), which belongs to this subfamily, and its ligand. The receptor is expressed in lymph node and peripheral blood leukocytes, and its expression is up-regulated in human peripheral mononuclear cells mainly after stimulation with anti-CD3/CD28 monoclonal antibodies or phorbol 12-myristate 13-acetate/ionomycin. AITR associates with TRAF1 (TNF receptor-associated factor 1), TRAF2, and TRAF3, and induces nuclear factor (NF)-kappaB activation via TRAF2. The ligand for AITR (AITRL) was found to be an undescribed member of the TNF family, which is expressed in endothelial cells. Thus, AITR and AITRL seem to be important for interactions between activated T lymphocytes and endothelial cells.

Comparison of primary coronary stenting to primary balloon angioplasty with stent bailout for the treatment of patients with acute myocardial infarction

This study compares the immediate and long-term outcomes of a primary coronary stenting strategy with primary balloon angioplasty with stent bailout in the treatment of patients with acute myocardial infarction (AMI). One hundred forty-seven consecutive patients who underwent primary balloon angioplasty with stent bailout (n = 94) or primary stenting (n = 53) for AMI were clinically followed for 8.1 +/- 5.7 and 8.5 +/- 4.5 months, respectively. Immediate results, as well as in-hospital and long-term ischemic events (death, reinfarction, and repeat revascularization) were compared between both groups. Angiographic success was 91.5% in the balloon angioplasty group and 94% in the stent group. In-hospital and late follow-up combined ischemic events were 22 of 94 (23%) versus 0 of 53 (0%); p < 0.001 and 33 of 78 (42%) versus 13 of 53 (25%), p = 0.04 for the balloon angioplasty and stent groups, respectively. At 6 months, the cumulative probability of repeat target lesion revascularization was higher in the balloon angioplasty group (47% vs 18%, p = 0.0006) as was the probability of late target revascularization (36% vs 18%, p = 0.046); the cumulative event-free survival after 6 months was significantly lower in the balloon angioplasty group (44% vs 80%, p = 0.0001). This study demonstrates that a primary stent placement strategy in patients with AMI is safe, feasible, and superior to primary balloon angioplasty with stent bailout. Primary stenting results in a larger postprocedural minimal luminal diameter, a lower early and late recurrent ischemic event rate, and a lower incidence of target lesion revascularization at follow-up.

Behavior of atherosclerotic plaque components after in vitro angioplasty and atherectomy studied by high field MR imaging

AIMS

Using magnetic resonance imaging (MRI), we developed in vitro models to image the response of fatty, fibrous, and calcified plaques to in vitro models of angioplasty and atherectomy, and tested the resistance of collagenous cap and lipid core to radial compression.

METHODS AND RESULTS

We studied the effects of balloon compression on 10 fibrous plaques with a complete collagenous cap (group A), 6 fatty plaques without cap (group B), and 5 calcified plaques (group C). Atherectomy was performed on nine other fibrous lesions (group D). In group A, fibrous cap, lipid core, and plaque did not change after radial compression despite a decrease in luminal obstruction due to medial stretching. In group B, a reduction of plaque (-30%) and lipid core (-35%) were observed. Compression dissected calcified plaques at the shoulder level. In group D, atherectomy reduced collagenous cap by 54%, and plaque by 35%.

CONCLUSIONS

In these models, MRI shows 1) the high resistance of collagenous caps to radial compression, 2) a stretching effect of compression on disease-free walls, enlarging lumen in case of fibrous plaque, but a reduction and redistribution of lipid cores in case of fatty plaques, 3) the rupture of calcified arteries at the plaque shoulder, and 4) the reduction of fibrous components by atherectomy but not by angioplasty. By characterizing plaque composition, MRI may allow a predictable response of atherosclerotic arteries to interventional procedures.

Human 4-1BB (CD137) signals are mediated by TRAF2 and activate nuclear factor-kappa B

Human 4-1BB (CD137), a member of the tumor necrosis factor receptor (TNFR) superfamily, costimulates T cell activation. No apparent intrinsic kinase activity is seen with 4-1BB, which suggests that 4-1BB-associated molecules may be involved in 4-1BB-mediated signal transduction. We found that tumor necrosis factor receptor-associated factor (TRAF) 1, TRAF2, and TRAF3, all interacted with the cytoplasmic domain of 4-1BB. Mutation analysis showed that TRAF1, TRAF2, and TRAF3 were associated with one of two runs of acidic residues found in the cytoplasmic domain of 4-1BB. In addition, 4-1BB cross-linking with TCR signal in Jurkat cells and overexpression of 4-1BB in 293 cells were able to induce activation of the nuclear factor-kappa B (NF-kappa B). 4-1BB-mediated NF-kappa B activation was inhibited by a dominant negative-TRAF2 or -NF-kappa B-inducing kinase (NIK). These data suggest that 4-1BB functions may be mediated by NF-kappa B activation, which requires a TRAF2/NIK pathway.

Alpha 2-antiplasmin causes thrombi to resist fibrinolysis induced by tissue plasminogen activator in experimental pulmonary embolism

BACKGROUND

In patients with pulmonary embolism, thrombi resist fibrinolysis induced by plasminogen activators. Because the molecular basis of this thrombus resistance is poorly understood, we used a potent inhibitor to examine the potential role of alpha 2-antiplasmin (alpha 2AP) in experimental pulmonary embolism.

METHODS AND RESULTS

Lysis of experimental pulmonary emboli was measured 4 hours after embolization in anesthetized ferrets. All animals received heparin (100 U/kg). Five experimental groups were studied: (1) no recombinant tissue plasminogen activator (rTPA); (2) rTPA at 1 mg/kg; (3) rTPA at 2 mg/kg; (4) rTPA at 1 mg/kg plus a control monoclonal antibody (MAb); and (5) rTPA at 1 mg/kg plus an alpha 2AP inhibitor (MAb 77A3). In comparison with ferrets receiving no rTPA (15.6 +/- 10.5% lysis, mean +/- SD), rTPA-treated groups showed significantly greater lysis (P < .01). Animals treated with rTPA and alpha 2AP inhibitor (56.2 +/- 4.7% lysis) showed significantly greater lysis than all other treatment groups, including ferrets treated with the same dose of rTPA alone (38.5 +/- 6.3%, P < .01), with twice the rTPA dose alone (45.0 +/- 6.5%, P < .05), or with a control MAb (35.2 +/- 4.6%, P < .01). The combination of rTPA treatment and alpha 2AP inhibition caused no consumption of fibrinogen.

CONCLUSIONS

Inhibition of alpha 2AP significantly amplified the lysis of experimental pulmonary emboli by rTPA without increasing fibrinogen consumption. These results suggest that alpha 2AP may play an important role in thrombus resistance in patients with venous thromboembolism.

Variability of platelet degranulation by different contrast media

RATIONALE AND OBJECTIVES

It has been suggested that nonionic but not ionic contrast media degranulate blood platelets when mixtures of blood and contrast media are studied by flow cytometry. This phenomenon was further assessed in the current study not only by performing whole-blood platelet flow cytometry but also by performing flowing blood platelet aggregometry. The latter is a highly sensitive measure of platelet function.

METHODS

Blood samples were collected from six normal donors and mixed with equal volumes of an ionic monomer (diatrizoate), a nonionic monomer (iohexol), an ionic dimer (ioxaglate), and a nonionic dimer (iodixanol). Samples were collected in the presence of no anticoagulant for 1 min prior to the addition of sodium citrate or in the presence of heparin (14.5 U/ml) or recombinant hirudin (60 micrograms/ml). All samples were fixed in formaldehyde within 30 min.

RESULTS

Platelet degranulation was observed with one nonionic agent (iohexol) and one ionic agent (diatrizoate). Degranulation was not seen with iodixanol or ioxaglate.

CONCLUSION

These findings indicate that degranulation is independent of the ionic or nonionic nature per se of contrast media. A possible explanation for this conclusion is suggested.

Transient thrombotic state after abrupt discontinuation of heparin in percutaneous coronary angioplasty

Clinical and biochemical evidence of a rebound phenomenon after discontinuing thrombin inhibitors has been reported in patients with unstable angina. To investigate if a similar phenomenon occurs in patients undergoing coronary angioplasty, 14 patients were prospectively studied during and after discontinuation of heparin infusion. A transient thrombotic state identified by a significant increase in a polypeptide fragment and fibrinopeptide A was observed 3 hours after abruptly discontinuing heparin infusion. This observation may be clinically important in managing patients after coronary angioplasty.

Morphologic characteristics of restenotic lesions following coronary interventions: balloon angioplasty versus directional atherectomy: can we speculate about the mechanism of restenosis from morphologic analysis?

In order to compare the processes of restenosis after balloon angioplasty as compared to that after directional coronary atherectomy, we performed qualitative and quantitative analysis of 72 lesions in 68 patients with recurrent ischemia following a successful initial procedure. For each lesion, we reviewed the pre-intervention, immediate post-intervention, and restenosis angiograms. The morphology of the restenotic lesions could not be predicted from pre- or post-intervention angiograms. The restenotic lesions after directional atherectomy, as compared to balloon angioplasty, did not show a statistically significant difference, although there was a trend to more eccentric narrowing.

A novel chemokine, macrophage inflammatory protein-related protein-2, inhibits colony formation of bone marrow myeloid progenitors

A new member of the beta-chemokine family, macrophage inflammatory protein (MIP)-related protein-2 (MRP-2) was isolated from a murine macrophage cell line, RAW 264.7. MRP-2 is composed of 122 amino acids of which the first 21 residues constitute a putative signal sequence. The putative mature protein is composed of 101 amino acids with a molecular weight of 11,600. MRP-2 is structurally similar to MIP-related protein-1 (MRP-1) (C10) and MIP-1 alpha. MRP-2 shows a 50.8% sequence identity at the protein level to MRP-1 and 46.3% identity to MIP-1 alpha. MRP-2 detects approximately 1.3 kilobase mRNA from monocyte and macrophage cell lines but does not detect the mRNA from T and B cells. The MRP-2 gene termed Scya9 was mapped to the central region of mouse chromosome 11 near the Scya1 and Scya2 genes, which are also members of the beta-chemokine superfamily. The Scya gene cluster was located between neurofibromatosis type 1 (Nf1) and myeloperoxidase (Mpo). rMRP-2 significantly suppressed colony formation by murine and human bone marrow granulocyte-macrophage (CFU-granulocyte-macrophage), erythroid (burst-forming unit-E), and multipotential (CFU-granulocyte-erythroid-macrophage-megakaryocyte) progenitor cells stimulated by combinations of growth factors.

A novel chemokine, macrophage inflammatory protein-related protein-2, inhibits colony formation of bone marrow myeloid progenitors

A new member of the beta-chemokine family, macrophage inflammatory protein (MIP)-related protein-2 (MRP-2) was isolated from a murine macrophage cell line, RAW 264.7. MRP-2 is composed of 122 amino acids of which the first 21 residues constitute a putative signal sequence. The putative mature protein is composed of 101 amino acids with a molecular weight of 11,600. MRP-2 is structurally similar to MIP-related protein-1 (MRP-1) (C10) and MIP-1 alpha. MRP-2 shows a 50.8% sequence identity at the protein level to MRP-1 and 46.3% identity to MIP-1 alpha. MRP-2 detects approximately 1.3 kilobase mRNA from monocyte and macrophage cell lines but does not detect the mRNA from T and B cells. The MRP-2 gene termed Scya9 was mapped to the central region of mouse chromosome 11 near the Scya1 and Scya2 genes, which are also members of the beta-chemokine superfamily. The Scya gene cluster was located between neurofibromatosis type 1 (Nf1) and myeloperoxidase (Mpo). rMRP-2 significantly suppressed colony formation by murine and human bone marrow granulocyte-macrophage (CFU-granulocyte-macrophage), erythroid (burst-forming unit-E), and multipotential (CFU-granulocyte-erythroid-macrophage-megakaryocyte) progenitor cells stimulated by combinations of growth factors.

Percutaneous mitral balloon valvotomy for recurrent mitral stenosis after surgical commissurotomy

Immediate outcome and 4-year follow-up results of percutaneous mitral balloon valvotomy (PMV) in patients with previous surgical mitral commissurotomy are studied. Repeat surgical mitral commissurotomy in patients with previous surgical commissurotomy is associated with higher mortality and morbidity. PMV has been proven to be safe and could be an ideal alternative in this patient group. The results of 68 patients with previous surgical commissurotomy were compared with those of 261 patients without prior surgical intervention. A good outcome, defined as the final mitral valve area > 1.5 cm2, was obtained in 51% of the patients with prior surgical commissurotomy compared with 71% in the control group (p = 0.002). During the 4-year follow-up period, there were more patients who required mitral valve replacement (19% vs 7%; p = 0.004) and who were in New York Heart Association functional class III and IV (85% vs 71%; p = 0.02) among those with prior surgical commissurotomy. However, when these patients were divided according to echocardiographic score, those with a score < or = 8 had immediate outcome and long-term results similar to those without prior commissurotomy. PMV can be performed safely in patients with prior surgical commissurotomy. Although results of long-term follow-up in these patients is not as good as those in patients without prior surgical commissurotomy, those with a low echocardiographic score had similar excellent long-term results.