Mid-term results of stent-less coronary intervention using rotational atherectomy and drug-coated balloon for de-novo lesions in hemodialysis patients.

BACKGROUND: Although drug-coated balloon (DCB)-based stent-less percutaneous coronary intervention (PCI) for de-novo lesions has attracted more attention, outcomes of the DCB procedure for hemodialysis (HD) patients are reported to be inferior to those for non-HD patients, similarly to drug-eluting stent (DES). Recent several reports have shown that rotational atherectomy (RA) followed by DCB treatment (RA/DCB) could be an option of revascularization strategy particularly for calcified de-novo lesions even in the new-generation DES era; however, efficacy of the RA/DCB procedure for HD patients remains unclear. METHODS: A total of 47 consecutive cases (53 lesions) undergoing RA/DCB for de-novo lesions were enrolled. According to the presence/absence of HD at baseline, the 47 cases were divided into the HD cases (N.=16) and the non-HD cases (N.=31), and the 53 lesions were divided into the HD lesions (N.=20) and the non-HD lesions (N.=33). RESULTS: The HD cases had a significantly lower prevalence of dyslipidemia and smoking than the non-HD cases. Final RA burr size, DCB diameter used, and angiographic success rate of PCI did not significantly differ between the 2 groups. Preprocedural, post-procedural, and follow-up QCA parameters were also similar between the 2 groups. Twelve-month clinical outcomes were comparable between the 2 groups. CONCLUSIONS: Mid-term outcomes of stent-less PCI using RA/DCB for de-novo lesions in HD patients might be comparable to those in non-HD patients, suggesting efficacy of pretreatment of RA prior to DCB treatment in HD patients.

Stentless Interventional Procedure Using Rotational Atherectomy and Drug-Coated Balloon for Noncalcified De Novo Lesions.

BACKGROUND: Several recent reports have shown that a stentless interventional procedure using rotational atherectomy followed by drug-coated balloon (DCB) treatment (RA/DCB) is a potent revascularization therapy for calcified de novo lesions even in the new-generation drug-eluting stent era; however, the role of the RA/DCB procedure for noncalcified de novo lesions remains unclear. METHODS: A total of 47 consecutive patients (53 lesions) who underwent RA/DCB for coronary de novo lesions were enrolled. According to the presence or absence of severe calcification at target lesions on fluoroscopy, the 47 patients were divided into the noncalcified cases (n = 12) and the calcified cases (n = 35), and the 53 lesions were divided into the noncalcified lesions (n = 14) and the calcified lesions (n = 39). RESULTS: The noncalcified cases tended to have a higher frequency of bleeding risk and had a significantly lower prevalence of dual antiplatelet therapy compared with the calcified cases. The main lesion-specific factors for the RA/DCB procedure among the noncalcified lesions were presence of left circumflex coronary artery ostial lesion. The final burr size, DCB diameter used, and angiographic success rate did not significantly differ between the 2 groups. The noncalcified lesions had a larger reference diameter and a shorter lesion length than the calcified lesions, whereas acute gain and late lumen loss did not differ between the 2 groups. Nine-month clinical outcomes were comparable between the 2 groups. CONCLUSIONS: Under drug-eluting stent-unsuitable clinical or lesion conditions, acute and midterm outcomes of RA/DCB for noncalcified de novo lesions might be comparable with those for calcified de novo lesions.

CONTEXTE: Plusieurs rapports récents ont montré qu'une revascularisation sans endoprothèse effectuée par athérectomie rotationnelle (AR) suivie d'un traitement par ballonnet médicamenté (BM) constitue une méthode efficace pour traiter les nouvelles lésions calcifiées, même à l'ère des endoprothèses médicamentées de nouvelle génération; on ne connaît toutefois pas bien l'utilité de l'intervention par AR et BM en cas de nouvelles lésions non calcifiées. MÉTHODOLOGIE: Au total, 47 patients consécutifs (53 lésions) ayant subi une intervention par AR et BM pour traiter de nouvelles lésions coronariennes ont été admis dans l'étude. Ces 47 patients ont été répartis en deux groupes, en fonction de l'absence (n = 12) ou de la présence (n = 35) de lésions . cibles sévèrement calcifiées observées à la fluoroscopie. Les 53 lésions ont aussi été réparties en deux groupes : lésions non calcifiées (n = 14) et lésions calcifiées (n = 39). RÉSULTATS: Les patients n'ayant pas de lésion calcifiée étaient généralement plus susceptibles de présenter des saignements et significativement moins nombreux à être sous bithérapie antiplaquettaire, comparativement aux patients ayant des lésions calcifiées. Dans le cas des lésions non calcifiées, la principale caractéristique justifiant une AR et un traitement par BM était la présence d'une lésion ostiale du rameau circonflexe de l'artère coronaire gauche. La taille de la dernière fraise utilisée, le diamètre du BM utilisé et le taux de réussite objectivée par angiographie étaient comparables dans les deux groupes. Les lésions non calcifiées avaient un diamètre de référence plus grand et étaient plus courtes que les lésions calcifiées, tandis que le gain aigu et la perte luminale tardive étaient similaires dans les deux groupes. Les résultats cliniques à neuf mois étaient aussi similaires dans les deux groupes. CONCLUSIONS: Lorsque les conditions cliniques ou les lésions ne se prêtent pas à l'utilisation d'une endoprothèse médicamentée, le traitement des nouvelles lésions non calcifiées par AR et BM pourrait donner des résultats immédiats et à moyen terme comparables à ceux du traitement des nouvelles lésions calcifiées.

Angiographic and Clinical Outcomes After Stent-less Coronary Intervention Using Rotational Atherectomy and Drug-Coated Balloon in Patients with De Novo Lesions.

OBJECTIVES: We investigated angiographic and clinical outcomes in patients with de novo lesions undergoing rotational atherectomy (RA) followed by drug-coated balloon (DCB) dilation (RA/DCB). BACKGROUND: Implantation of drug-eluting stent (DES) has been a mainstay of the interventional treatment of coronary artery disease (CAD); however, there still remain several DES-unsuitable clinical/lesion conditions. Nowadays DCB for de novo lesions has attracted more attention, and RA, which tends not to cause major dissection but to debulk intima, might be one of suitable pre-treatments before DCB. METHODS AND RESULTS: Thirty patients (34 lesions) undergoing RA/DCB for de novo lesions were enrolled. Clinical/lesion background included severe calcification, calcified nodule, inlet/outlet of aneurysm, ostial lesion, severe thrombocytopenia, bleeding tendency, and/or sequelae of Kawasaki disease. The largest burr size used was 1.83 ±â€¯0.23 mm, and the mean DCB diameter was 2.71 ±â€¯0.47 mm. Angiographic success was obtained in 94% of the lesions. No acute closure but 1 no reflow occurred. Repeat angiography (mean, 6.6 months after procedure) was performed for 19 lesions. Frequency of binary restenosis was 21.1%, and late lumen loss was 0.34 ±â€¯0.30 mm. During a mean follow-up period of 13.1 months, 6 deaths (2 sudden deaths, 1 cardiac death, 3 non-cardiac deaths), 2 strokes, and 2 target lesion revascularizations were observed. CONCLUSIONS: Stent-less PCI using RA/DCB might be an alternative revascularization therapy for CAD patients complicated with DES-unsuitable conditions.

Effects of Baseline Thrombocytopenia on In-hospital Outcomes in Patients Undergoing Elective Percutaneous Coronary Intervention.

Objective The purpose of the present study was to examine the relationship between thrombocytopenia at baseline and in-hospital outcomes in unselected patients undergoing elective percutaneous coronary intervention (PCI) in Japan. Methods Among a total of 1,247 consecutive elective PCI-treated patients, patients with a baseline platelet count 150,000-449,000/µL and 50,000-149,000/µL were assigned to the normal platelet (n=1,009) and thrombocytopenia (n=226) groups, respectively. The thrombocytopenia group was further divided into the mild thrombocytopenia (100,000-149,000/µL, n=187) and moderate thrombocytopenia (50,000-99,000/µL, n=39) groups. Results The angiographic success rate of PCI and in-hospital mortality rate did not differ to a statistically significant extent between the normal platelet and thrombocytopenia groups or between the mild thrombocytopenia and moderate thrombocytopenia groups, whereas the moderate thrombocytopenia group had a significantly higher rate of access site-related bleeding complications than the normal platelet group. According to a multivariate analysis, moderate thrombocytopenia was an independent predictor of access site-related bleeding complications. Conclusion Among patients with mild to moderate thrombocytopenia, elective PCI might be feasible and effective in the short term; however, more attention should be paid to access site-related bleeding complications, particularly in patients with moderate thrombocytopenia.

Potent Stent-Less Procedure Using Rotational Atherectomy and Drug-Coated Balloon to Right Coronary Ostial Lesion.

BACKGROUND: Even in the drug-eluting stent era, ostial lesion of the right coronary artery (RCA) still remains therapeutic challenge for interventional cardiologists. Case Series Case 1 (76 y.o. male) with angina on effort underwent transradial stent-less percutaneous coronary intervention (PCI) using rotational atherectomy (RA) followed by drug-coated balloon (DCB) dilation alone (RA/DCB) against a calcified de novo RCA ostial lesion. Case 2 (86 y.o. female) with recurrent unstable angina and hemodialysis underwent transfemoral RA/DCB against a severe repeat in-stent restenosis probably due to calcified nodule in the RCA ostium. In the both patients, PCI was successfully completed under intravascular ultrasound imaging (IVUS) guidance without complications. Follow-up CAG performed 4-5 months after the procedure revealed no significant lumen narrowing in the both RCA ostial lesions. CONCLUSIONS: The both cases suggest that stent-less PCI using RA/DCB under IVUS might be an alternative revascularization therapy of choice for calcified RCA ostial lesions.

Bifurcation Intervention in Single Coronary Artery.

A 77-year-old man was referred to our hospital for angina on effort. Coronary angiography and computed tomography demonstrated a single coronary artery arising from the right sinus of Valsalva. The left circumflex coronary artery (LCx) anomalously deriving near from the ostium of right coronary artery exhibited severe stenosis in the bifurcation of the obtuse marginal branch. Although the bifurcation lesion still remains a therapeutic challenge for guide extension catheter (GEC)-based percutaneous coronary intervention, under the guidance of intravascular ultrasound imaging, we successfully implanted an everolimus-eluting stent at the bifurcated LCx lesion and performed kissing balloon inflation using 0.014- and 0.010-inch systems through GECs.

Stent-less percutaneous coronary intervention using rotational atherectomy and drug-coated balloon: A case series and a mini review.

BACKGROUND: Experiences of rotational atherectomy (RA) followed by drug-coated balloon (DCB) dilation alone (RA/DCB) for de novo coronary artery lesion have been limited. CASE SERIES: Case 1 (65 year-old male) with silent myocardial ischemia and hemodialysis had old anterior myocardial infarction and intact LM/LCx, and underwent RA/DCB against a diffuse calcified lesion in the proximal LAD and a tandem lesion in the proximal RCA. Case 2 (88 year-old female) with post-infarction unstable angina had severe thrombocytopenia and anemia due to myelodysplastic syndrome (platelet 6000/µL, hemoglobin 8.3 g/dL), and underwent RA/DCB against a severe stenosis in the mid LCx after transfusions. Case 3 (47 year-old male) with silent myocardial ischemia due to possible sequelae of Kawasaki disease underwent RA/DCB against a restenotic lesion at the in-let of the calcified aneurysm in the proximal LAD. In all of the patients, PCI was successfully completed under optical frequency domain imaging (OFDI) without complications. Follow-up CAG performed 6-7 months after the procedure revealed no restenosis in case 1 and case 3, and all of the 3 cases have been free of cardiovascular/hemorrhagic events for 11-37 months since the last stent-less procedures. CONCLUSIONS: These cases suggest that RA/DCB under OFDI might be an alternative stent-less revascularization therapy of choice for patients who may be unsuitable for drug-eluting stent implantation.

Rotational Atherectomy Followed by Drug-Coated Balloon Dilation for Left Main In-Stent Restenosis in the Setting of Acute Coronary Syndrome Complicated with Right Coronary Chronic Total Occlusion.

An 83-year-old man presented with recurrent acute coronary syndrome (ACS) at the left main coronary artery (LMCA) complicated with ostial chronic total occlusion (CTO) in the right coronary artery (RCA) (RCA-CTO). At the first LMCA-ACS approximately 1 year earlier, he had undergone LMCA-crossover stenting with a biolimus-eluting stent in the presence of RCA-CTO. At the second LMCA-ACS, we angiographically confirmed severe in-stent restenosis in the distal LMCA, in addition to angled severe stenosis in the just proximal LCx, and performed primary PCI for the LMCA bifurcation lesion under intra-aortic balloon pumping support. Because of difficulty in crossing a guidewire through the just proximal LCx lesion, we first performed rotational atherectomy against the LMCA in-stent eccentric lesion. After successfully crossing the guidewire into the LCx, we added balloon dilation with kissing balloon inflation followed by alternate drug-coated balloon dilation. An eight-month follow-up coronary angiography revealed no further vessel narrowing in the LMCA bifurcation lesion.

Primary Percutaneous Coronary Intervention Followed by Valve Surgery for Acute Coronary Syndrome at Left Main Trunk Complicated With Severe Aortic Stenosis.

An 89-year-old woman appeared to have acute coronary syndrome at the left main trunk (LMT) complicated with severe aortic stenosis, moderate-severe mitral regurgitation, depressed left ventricular (LV) function, and multivessel disease. Because of sustained hypotension even under intra-aortic balloon pumping support during emergency coronary angiograhy, we performed primary percutaneous coronary intervention solely for the LMT lesion using a bare metal stent, leading to recovery from the shock state. On the second hospital day, based on our heart-team consensus, we performed aortic valve replacement and coronary artery bypass grafting surgery, and added edge-to-edge repair (Alfieri stitch) of the mitral valve, resulting in complete revascularization and dramatically improved LV function.

Relationship Between Mean Blood Pressure at Admission and In-Hospital Outcome After Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction.

A J-shaped or U-shaped curve phenomenon might exist between systolic blood pressure (SBP) or pulse pressure (PP) at admission and in-hospital mortality in Japanese patients with acute myocardial infarction (AMI) undergoing primary percutaneous coronary intervention (PCI). However, data regarding a relationship between mean blood pressure (MBP) at admission and in-hospital outcome in AMI patients undergoing primary PCI are still lacking in Japan.A total of 1,413 primary PCI-treated AMI patients were classified into quintiles based on admission MBP (< 79 n = 283, 79-91 n = 285, 92-103 n = 285, 104-115 n = 279, and ≥ 116 mmHg n = 281). Patients with MBP < 79 mmHg had a significantly higher in-hospital mortality, while mortality was not significantly different among the other quintiles: 16.6% (< 79), 4.9% (79-91), 3.9% (92-103), 3.2% (104-115), and 5.0% (≥ 116 mmHg). On multivariate analysis, Killip class ≥ 3 at admission, LMT or multivessels as culprit lesions, admission MBP < 79 mmHg, and age were independent positive predictors of in-hospital mortality, whereas hypercholesterolemia and TIMI 3 flow before/after PCI were negative predictors, while the other MBP categories were not.These results suggest that admission MBP < 79 mmHg might be associated with in-hospital death, and the in-hospital prognostic effects of MBP, the steady component of blood pressure, at admission might be different from those of SBP or PP, the pulsatile component of blood pressure, at admission in Japanese AMI patients undergoing primary PCI.

Rotational Atherectomy Followed by Drug-Coated Balloon Dilation in Possible Coronary Sequelae of Kawasaki Disease.

Rotational atherectomy with/without low-pressure balloon dilation has been a mainstay of interventional treatment for stenosis due to the coronary sequelae of Kawasaki disease (KD). Here, we report a restenosis case of probable coronary sequelae of KD treated with rotational atherectomy with low-pressure 2.5-mm balloon dilation 6 months previously. Under the guidance of optical frequency domain imaging, we performed rotational atherectomy followed by 2.5-mm drug-coated balloon (DCB) dilation for an atherosclerotic restenosis at the inlet of a calcified aneurysm in the proximal left anterior descending coronary artery. Coronary angiography 6 months later showed no apparent progression of vessel narrowing, and we could defer repeat intervention. The present case suggests that rotational atherectomy followed by DCB dilation could be an alternative revascularization therapy of choice in coronary KD sequelae complicated with atherosclerosis.

Survivors of acute myocardial infarction at left main trunk undergoing primary percutaneous coronary intervention.

Acute myocardial infarction (AMI) at left main trunk (LMT) is a deteriorated condition with high in-hospital morbidity and mortality; however, detailed data regarding AMI patients with LMT as culprit lesion (LMT-AMI patients) undergoing primary percutaneous coronary intervention (PCI) has been still limited. Using the AMI-Kyoto Multi-Center Risk Study database, clinical background, angiographic findings and results of primary PCI were retrospectively compared between primary PCI-treated LMT-AMI patients without in-hospital death (survivors, n = 21) and those with in-hospital death (non-survivors, n = 19). The survivors had higher values of estimated glomerular filtration rate (eGFR) and systolic blood pressure at admission and lower prevalence of Killip grade 4 than the non-survivors. Pre-procedural thrombolysis in myocardial infarction (TIMI) flow grade ≥2 at the initial coronary angiography (CAG) and post-procedural TIMI flow grade 3 at the final CAG were more frequent in the survivors, compared with the non-survivors. In contrast, age and gender did not differ significantly between the two groups. On multivariate analysis, higher eGFR and Killip grade 4 at admission were found to be independent in-hospital prognostic factors in the LMT-AMI patients. Admission eGFR and Killip grade 4 are tightly associated with in-hospital prognosis in LMT-AMI patients undergoing primary PCI.

Usefulness of continuous compression using TR Band™ for radial arteriovenous fistula following trans-radial intervention.

Arteriovenous fistula (AVF) after trans-radial catheterization is an extremely rare complication. A 61-year-old man experienced a painful swelling in the left radial punctured site. The findings of vascular ultrasound and angiography led to a diagnosis of an iatrogenic radial AVF. We performed continuous compression using a hemostatic band for 24 h after which the radial AVF completely disappeared without vessel occlusion, and no relapse occurred. Eight cases of catheterization-induced radial AVF have been mentioned in the literature, but the treatment has not been noninvasive in any case. This is the first report of an iatrogenic radial AVF that was noninvasively repaired using continuous low-pressure compression with a hemostatic band. .

Early inflammatory reactions in atherosclerosis are induced by proline-rich tyrosine kinase/reactive oxygen species-mediated release of tumor necrosis factor-alpha and subsequent activation of the p21Cip1/Ets-1/p300 system.

OBJECTIVE: Reactive oxygen species (ROS) are involved in the initial process of atherosclerosis, whereas it remains to be determined how atherogenic stimulus causes ROS-mediated proinflammatory reactions. Here, we focused on proline-rich tyrosine kinase (PYK2)-mediated ROS generation and examined how atherogenic stimulus causes early proinflammatory reactions. METHODS AND RESULTS: PYK2-deficient (knockout [KO]) (PYK2-KO) mice were crossbred with apolipoprotein E (ApoE)-deficient (PYK2-KO/ApoE-KO) mice. PYK2-KO/ApoE-KO mice and endothelial cells (EC) were used for the study. Aortic atherogenic lesions in PYK2-KO/ApoE-KO mice were markedly decreased (55% versus ApoE-KO) after 8 weeks of a Western diet. Aortic PYK2 was activated as early as 7 days after the Western diet, when inflammatory cells were not yet activated. Addition of the proatherogenic oxidized phospholipid lysophosphatidylcholine caused activation of endothelial PYK2. Lysophosphatidylcholine-activated PYK2 induced NADPH oxidase-mediated ROS generation and ROS-mediated synthesis of tumor necrosis factor-α (TNFα), vascular cell adhesion molecule-1 (VCAM-1), monocyte chemotactic protein-1 (MCP-1), and p21Cip1/Ets-1. Neutralizing anti-TNFα antibody or knockdown of p21Cip1/Ets-1 system blocked the induction of VCAM-1 and MCP-1. PYK2 deficiency abolished these ROS-mediated proinflammatory reactions. Further analysis revealed that PYK2/ROS-mediated p21Cip1/Ets-1 activation upregulated the transcription of the MCP-1 gene in collaboration with p300 transcription coactivator. CONCLUSIONS: PYK2 is a key tyrosine kinase activated by high cholesterol exposure, which causes ROS-mediated TNFα release and induces TNFα-dependent expression of proinflammatory molecules via the p21Cip1/Ets-1/p300 transcription system.

Endothelial FGF receptor signaling accelerates atherosclerosis.

Members of the fibroblast growth factor (FGF) family have been clinically applied to the treatment of ischemic diseases because of their strong angiogenic actions. Although tissue ischemia is predominantly caused by atherosclerosis, the roles of endothelial FGF receptors (FGF-Rs) in atherosclerosis remain obscure. We generated endothelial cell (EC)-targeted constitutively active FGF-R2-overexpressing mice, using the Tie2 promoter (Tie2-FGF-R2-Tg), and crossed them with apolipoprotein E (ApoE)-deficient mice (ApoE-KO) to generate Tie2-FGF-R2-Tg/ApoE-deficient mice (Tie2-FGF-R2-Tg/ApoE-KO). After being fed a Western diet for 8 wk, the Tie2-FGF-R2-Tg/ApoE-KO demonstrated 2.0-fold greater atherosclerotic lesion area on the luminal surfaces of the aortas than the ApoE-KO (P < 0.01). The level of p21(Cip1) protein, a cell cycle inhibitor, in the FGF-R2-overexpressing EC was 2.5-fold greater than that in the wild-type (WT) EC at the baseline (P < 0.01). FGF-R2 overexpression in the EC resulted in increased expression of VCAM-1 and ICAM-1, acceleration of apoptosis, and decreased proliferative activity, all of which were normalized by small interfering RNA (siRNA)-mediated knockdown of p21(Cip1) (75% reduction in protein level, P < 0.01). Furthermore, the expression of PDGF-B and Egr-1, a PDGF/p21(Cip1)-inducible transcription factor, in the aortic endothelium of Tie2-FGF-R2-Tg/ApoE-KO was significantly greater than that in ApoE-KO. The proliferation of vascular smooth muscle cells in the aortic media of Tie2-FGF-R2-Tg/ApoE-KO was 2.0-fold higher than that in ApoE-KO (P < 0.01). Thus our study reveals that endothelial FGF-R2 signaling aggravates atherosclerosis by promoting p21(Cip1)-mediated EC dysfunction and cautions against the use of FGF for therapeutic angiogenesis in the setting of atherosclerosis.

Importance of measuring the fractional flow reserve in patients receiving hemodialysis.

Angiography is not always an accurate indicator of physiologically significant stenosis. We examined the usefulness of functional evaluation of coronary stenosis severity by determining the fractional flow reserve (FFR) using a pressure wire in patients who received hemodialysis with angiographically intermediate lesions. We recruited 44 patients with intermediate lesions; of these, 22 were undergoing hemodialysis while 22 were not. Quantitative coronary angiography (QCA) was performed to measure the minimal lumen diameter (MLD) and calculate the percent diameter stenosis (%DS). The FFR was calculated as the ratio of the coronary pressure at the distal stenotic site to the mean aortic pressure during maximum hyperemia. In each group, we investigated the relationship between the FFR and %DS and FFR and MLD. The patients in the hemodialysis group were significantly younger and had more calcified and type B2/C lesions than those in the non-dialysis group. Although the FFR was correlated with both %DS (r = 0.71, p < 0.01) and MLD (r = 0.58, p < 0.01) in the non-dialysis group, the FFR was not correlated with either MLD or %DS in the hemodialysis group. In the hemodialysis group, there was a discordance between the QCA- and FFR-based assessments of the severity of coronary stenosis. In patients receiving hemodialysis, both anatomical and functional assessments should be conducted to determine the physiological significance of the stenosis accurately.

[Clinical characteristics of patients diagnosed as high cardiac event probability by "Heart Risk View"].

"Heart Risk View" is the software to evaluate the cardiac event probability, and it is based on the results of the prospective cohort study (J-ACCESS). We examined the usefulness of this software. Study population consisted of 83 patients, who were diagnosed that cardiac event probability was over 20% by "Heart Risk View." During the follow-up period (596 +/- 356 days), cardiac event occurred in 23 patients (27.7%), including 7 patients death. No significant differences were observed in the ejection fraction by Quantitative Gated SPECT, total defect score calculated from SPECT, and the percentage of stress perfusion abnormality detected by SPECT between event and non-event groups. However, the percentage of cardiac revascularization therapy based on the SPECT was significantly lower in the event group (9 vs. 38%, p = 0.03). In conclusion, cardiac event probability calculated by "Heart Risk View" was reliable in our study cohort. Cardiac event strongly depended on the cardiac ischemia, for which the therapy was difficult because of lesion complexity or combined diseases.

Pressure-mediated hypertrophy and mechanical stretch induces IL-1 release and subsequent IGF-1 generation to maintain compensative hypertrophy by affecting Akt and JNK pathways.

RATIONALE: It has been reported that interleukin (IL)-1 is associated with pathological cardiac remodeling and LV dilatation, whereas IL-1beta has also been shown to induce cardiomyocyte hypertrophy. Thus, the role of IL-1 in the heart remains to be determined. OBJECTIVE: We studied the role of hypertrophy signal-mediated IL-1beta/insulin-like growth factor (IGF)-1 production in regulating the progression from compensative pressure-mediated hypertrophy to heart failure. METHODS AND RESULTS: Pressure overload was performed by aortic banding in IL-1beta-deficient mice. Primarily cultured cardiac fibroblasts (CFs) and cardiac myocytes (CMs) were exposed to cyclic stretch. Heart weight, myocyte size, and left ventricular ejection fraction were significantly lower in IL-1beta-deficient mice (20%, 23% and 27%, respectively) than in the wild type 30 days after aortic banding, whereas interstitial fibrosis was markedly augmented. DNA microarray analysis revealed that IGF-1 mRNA level was markedly (approximately 50%) decreased in the IL-1beta-deficient hypertrophied heart. Stretch of CFs, rather than CMs, abundantly induced the generation of IL-1beta and IGF-1, whereas such IGF-1 induction was markedly decreased in IL-1beta-deficient CFs. IL-1beta released by stretch is at a low level unable to induce IL-6 but sufficient to stimulate IGF-1 production. Promoter analysis showed that stretch-mediated IL-1beta activates JAK/STAT to transcriptionally regulate the IGF-1 gene. IL-1beta deficiency markedly increased c-Jun N-terminal kinase (JNK) and caspase-3 activities and enhanced myocyte apoptosis and fibrosis, whereas replacement of IGF-1 or JNK inhibitor restored them. CONCLUSIONS: We demonstrate for the first time that pressure-mediated hypertrophy and mechanical stretch generates a subinflammatory low level of IL-1beta, which constitutively causes IGF-1 production to maintain adaptable compensation hypertrophy and inhibit interstitial fibrosis.

Endothelium-targeted overexpression of constitutively active FGF receptor induces cardioprotection in mice myocardial infarction.

Fibroblast growth factor receptor (FGFR) is expressed in a variety of cells and is involved in their proliferation/migration/survival. To elucidate FGFR-mediated specific action of vascular endothelial cells (ECs) on myocardial ischemia, we generated endothelium-targeted transgenic mice overexpressing constitutively active FGFR2 using Tie2 promoter (FGFR2-Tg). Infarct size, vessel formation and blood perfusion were significantly improved 28 days after myocardial infarction (MI) in FGFR2-Tg, compared with wild-type mice. Aortic ECs isolated from FGFR-Tg showed a marked increase in migratory capacity and tube formation. These in vitro angiogenic activities were blocked by PI3-kinase inhibitor. Whereas, parameters obtained from echocardiography were already improved at three days after MI. Cardiomyocyte apoptosis at the ischemic border zone was decreased in FGFR2-Tg (32.1%, p < 0.05) and cardiac mRNA expression of FGF2 (basic FGF) was also up-regulated (142%, p < 0.05) at 3 days after MI. 1% oxygen-mediated apoptosis was significantly inhibited in FGFR2-Tg-ECs and this inhibition was abolished by PI3-kinase inhibitor. FGFR2-Tg-ECs exposed to 1% oxygen exhibited enhanced phosphorylation of 416-Tyr-Src, 473-Ser-Akt, and HIF1alpha accumulation. The production of FGF2 was enhanced 2.1-fold in FGFR-Tg-ECs under 1% oxygen via the Src/Akt/HIF1alpha pathway, which induced the peri-vessel migration of vascular smooth muscle cells (VSMCs) and anti-apoptotic effects on VSMCs and cardiomyocytes. FGF receptor signaling in ECs promoted migration, survival and autocrine production of FGF2, leading to reduced infarct size, which is associated with anti-apoptotic action in the early stage and with enhanced angiogenesis in the late stage after MI.