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lthough success rates of percutaneous coronary intervention (PCI) are high, PCI of bifurcation lesions is associated with a relatively low success rate and a relatively high incidence of procedural complications, including side branch occlusion and myocardial infarction. . [1][2][3][4][5] Meier et al were among the first to identify the risk of side branch occlusion associated with parent vessel angioplasty. 1 They emphasized that side branches involved in vessel narrowing are at high risk for side branch occlusion during PCI. Boxt et al has reported that vessels with angiographic ostial stenosis >50% have a higher risk of occlusion than those without ostial stenosis. 2 Prior studies have demonstrated that intravascular ultrasound (IVUS) provides information not generated by angiography alone, and the use of sonographic measurements of vascular dimensions has improved short-and long-term outcomes. 6-10 Despite several lines of evidence suggesting that IVUS guidance can reduce the need for target lesion revascularization after PCI, 9,10 it remains controversial whether preintervention IVUS findings can help to identify side branches likely to occlude after PCI of bifurcation lesions.We examined whether preintervention IVUS provides information not available by angiography alone and if it can be used to predict side branch occlusion after PCI. Circulation Journal Vol.69, March 2005 Methods Lesions and the Patient PopulationThe study group consisted of 105 bifurcation lesions in 96 patients with coronary artery disease, all of which had undergone preintervention IVUS examination in the native coronary artery. No directional coronary atherectomy, rotational atherectomy, nor thrombectomy were performed. The clinical diagnoses included: acute myocardial infarction (AMI) (57%), stable angina pectoris (17%), unstable angina pectoris (15%), and previous myocardial infarction (11%). We studied bifurcation lesions involving the main branch and the ostium of the side branch. 11 Only side branches with an estimated reference luminal diameter of 1 mm or greater were considered. Twenty-four lesions were excluded for the following reasons: kissing balloon technique or sequential dilatation was performed (n=6) and extensive target lesion calcification or artifacts which precluded accurate cross-sectional evaluation of the vessel involved (n=18). The remaining 81 bifurcation lesions in 72 patients were studied.Side branch occlusion was defined as a thrombolysis in myocardial infarction (TIMI) flow of ≤2 by the final angiogram after PCI procedures. 12 Quantitative Coronary AngiographyAngiograms were reviewed before introduction of coronary guidewire and after balloon dilation or stent deployment. The coronary flow pattern of side branches was graded according to the classification system of the TIMI trial. 12 Angiograms were digitized and analyzed using an automated edge-detection algorithm (QCA-CMS, version 4.0, Medical Imaging Systems, Rotterdam, The Netherlands).

An exaggerated increase in systolic blood pressure prolongs myocardial relaxation and increases left ventricular (LV) chamber stiffness, resulting in an increase in LV filling pressure. We hypothesize that patients with a marked hypertensive response to exercise (HRE) have LV diastolic dysfunction leading to exercise intolerance, even in the absence of resting hypertension. We recruited 129 subjects (age 63 ± 9 years, 64% male) with a preserved ejection fraction and a negative stress test. HRE was evaluated at the end of a 6-min exercise test using the modified Bruce protocol. Patients were categorized into three groups: a group without HRE and without resting hypertension (control group; n =30), a group with HRE but without resting hypertension (HRE group; n =25), and a group with both HRE and resting hypertension (HTN group; n =74). Conventional Doppler and tissue Doppler imaging were performed at rest. After 6-min exercise tests, systolic blood pressure increased in the HRE and HTN groups, compared with the control group (226 ± 17 mmHg, 226 ± 17 mmHg, and 180 ± 15 mmHg, respectively, p <0.001). There were no significant differences in LV ejection fraction, LV end-diastolic diameter, and early mitral inflow velocity among the three groups.However, early diastolic mitral annular velocity (E′) was significantly lower and the ratio of early diastolic mitral inflow velocity (E) to E′ (E/E′) was significantly higher in patients of the HRE and HTN groups compared to controls (E′: 5.9 ± 1.6 cm/s, 5.9 ± 1.7 cm/s, 8.0 ± 1.9 cm/s, respectively, p <0.05). In conclusion, irrespective of the presence of resting hypertension, patients with hypertensive response to exercise had

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