Keiichi Tsuchida

Association between coronary endothelial dysfunction and local inflammation of atherosclerotic coronary arteries

We have examined a possibility whether or not severity and extent of coronary atherosclerosis may associate with degree of local inflammation in relation to endothelial dysfunction as is indicated by reduced NO formation. Blood samples were obtained from aortic root (Ao) and coronary sinus (CS) of 39 patients who underwent coronary angiography. Plasma NOx levels (nitrite + nitrate, stable NO end-products) were evaluated by HPLC-Griess system, and markers of inflammation, C-reactive protein (CRP) and serum amyloid A protein (SAA), were measured by Latex Turbidimetric Immunoassay. To evaluate the changes of these substances through coronary circulation, the percentage changes of respective markers [(CS — Ao) x 100/Ao] were calculated. The extent and severity of atherosclerosis of left coronary arteries were evaluated with Gensini Score (GS). The GS correlated with the percentage changes of NOx (r = -0.35, p < 0.05) and that of SAA (r = 0.43, p < 0.05) across coronary circulation, but not with changes in CRP. Moreover, the percentage changes of NOx correlated with that of SAA (r = -0.36, p < 0.05). These results indicated that severity and extent of coronary atherosclerosis related to degree of local inflammation which has a possible association with coronary endothelial dysfunction. (Mol Cell Biochem 249: 67–73, 2003)

Exercise Induced Atrioventricular Block with Gap Phenomenon in Atrioventricular Conduction

A 54‐year‐old man with normal atrioventricuiar (AV) conduction at rest gave a 4‐year history of presyncope during exercise. Treadmill testing showed exercise induced AV block. Electrophysiological study demonstrated rate dependent infranodal AV block and abnormal refractory period of the His‐Purkinje system. The gap phenomenon in AV conduction occurred during the programmed stimulation. Supernormal conduction could be considered as the mechanism of the gap phenomenon in this patient.

Improved cardiac function after sirolimus-eluting stent placement in diabetic patients by pioglitazone: Combination therapy with statin

BACKGROUND Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists are used as anti-diabetic drugs, and their pleiotrophic action has been reported to improve endothelial function leading to cardioprotective effects. In this study we evaluated the long-term effect of pioglitazone on cardiac function in diabetic patients after percutaneous coronary intervention (PCI) by drug-eluting stent (DES). METHODS AND RESULTS We investigated 54 diabetic patients who received PCI using a sirolimus-eluting stent. We excluded cases of acute myocardial infarction. They were divided into two groups: Group C received only conventional therapy (n=26) and Group P received additionally pioglitazone 15 mg/day (n=28). The left ventricular ejection fraction (LVEF) was measured by left ventriculography and analyzed before and 8 months after PCI. In Group C, LVEF did not change significantly: 55.6% vs. 56.7%, before and after PCI respectively (p=0.58). However, pioglitazone significantly improved LVEF: 54.4% vs. 60.0% (p=0.014). Multiple linear regression analysis showed that DeltaLVEF was significantly related to pioglitazone therapy (p=0.037). In particular, the combination of pioglitazone and statin improved LVEF (DeltaLVEF 9.6% with vs. 2.2% without statin). CONCLUSIONS Pioglitazone improved cardiac function after PCI using SES in diabetic patients, especially in combination with a statin.

Two-wire protection of side branches to prevent side branch occlusion during stent implantation for bifurcational lesions

To prevent side branch occlusion during bifurcational lesion stenting, the placement of a wire in both the main branch and side branch is performed for “side-branch protection”. However, this procedure does not always prevent side branch occlusion. A procedure for placing two wires in the side branch, called “two-wire protection of side branches”, is considered to be more likely to prevent occlusion compared with one-wire protection of the side branch. We report on three cases in which “two-wire protection of side branches” was effectively performed during the stenting of bifurcational lesions.

Analysis of postextrasystolic relaxation response in the human heart

Postextrasystolic potentiation is the phenomenon in which ventricular contractile force is strengthened by a preceding premature beat. However, the response of diastolic function after an extrasystole is unknown. We studied 58 patients with chronic heart failure (CHF) and two control subjects to evaluate the response of relaxation following extrasystole. At cardiac catheterization, from the derivative of the left ventricular (LV) pressure, the ratio of LV peak negative dP/dt (–dP/dt) of a postextrasystole to a basal beat was calculated and defined as the postextrasystolic relaxation response (PRR). PRR was compared with parameters of left ventriculography: LV end-diastolic volume index (EDVI), LV end-systolic volume index (ESVI), and LV ejection fraction (EF). The PRRs of the two control subjects were 0.80 and 0.84. The mean PRR of the CHF patients was 0.99 ± 0.15. In all subjects, including patients and controls, correlation analysis between (EDVI, ESVI, and EF) and PRR yielded the following: (a) EDVI vs. PRR: R = 0.273, p = 0.036; (b) ESVI vs. PRR: R = 0.446, p < 0.001; and (c) EF vs. PRR: R = –0.520, p < 0.001. Thus, normal or non-failing human hearts showed a decline of –dP/dt in postextrasystole compared with the basal beats, but failing hearts had potentiated relaxation following an extrasystole.

Treating coil migration in combination therapy involving stenting and coiling for a wide-necked renal aneurysm

A man with a wide-necked renal artery aneurysm underwent combination therapy involving stenting and coiling to embolize it. However, a large section of one of the coils had migrated outside the stent implanted across the orifice of the aneurysm. After repositioning the migrated coil inside the stent, the implantation of another stent together with sandwiching of the coil between two stents repaired the prolapsed coil. This report describes precautions that should be taken during combination therapy involving stenting and coiling to embolize a wide-necked aneurysm.

A case of intracoronary protruded thrombus caused after bailout stenting for side branch occlusion

A 69-year-old woman underwent percutaneous coronary intervention for a severe stenotic lesion in the bifurcation of the mid-left anterior descending artery and first diagonal branch. A single stent was implanted into the left anterior descending artery. After the stent strut was dilated by balloon inflation in the diagonal branch, dissection occurred at the ostium of the diagonal branch and resulted in side branch occlusion due to hematoma. Bailout stenting was performed in the diagonal branch, but thrombus projection occurred in the left anterior descending artery. Aspiration, balloon inflation and thrombolytic therapy were performed, but distal embolism developed. This case illustrates that thrombus projection caused by stenting in a side branch may occur as a rare complication in percutaneous coronary intervention.