经皮激光心肌血管重建术对心脏去神经和心肌缺血作用的临床研究

目的目前国内外对经皮激光心肌血管重建术（PMR）的疗效和作用机制有很大争议。本研究目的在于评价PMR是否能改善顽固性心绞痛患者的临床症状和心肌缺血的客观指标,以及PMR对心脏的去神经作用,探讨PMR的临床疗效和可能的作用机制。方法30例顽固性心绞痛进行冠状动脉造影后不适合冠状动脉介入和外科冠状动脉旁路移植术治疗的患者,被随机分为两组：经皮激光心肌血管重建组17例和药物治疗组13例,随访（11．6±4．9）个月。经皮激光心肌血管重建术前、术后60min和术后1年冠状窦采全血,ELISA测定去甲肾上腺素和肾上腺素浓度,Hoher分析心率变异性（HRV）、心肌缺血总负荷（TIB）和缺血性ST段事件（STI）,心肌核素显像检查心肌灌注情况。结果PMR组17例患者中1例出现非持续性室性心动过速;2例打孔后出现心包压塞;1例于术后24h出现心力衰竭。药物治疗组无严重并发症发生。PMR组术后1年心绞痛级别下降1．7±0．3,与药物治疗组相比,差异有统计学意义（P〈0．05）。运动耐量比药物治疗组有增加趋势,但未达到统计学j蕞义。心肌缺血总负荷、缺血性sT段事件、心肌灌注情况术后24h和术后1年两组间差异均无统计学意义。PMR组术后60min冠状窦去甲肾上腺素和肾上腺素含量明显低于药物治疗组（P〈0．05）,但术后1年两组间差异无统计学意义;PMR组术后24h心率变异性显著高于药物治疗组（P〈0．05）,但是术后1年两组间差异无统计学意义。结论PMR虽然能改善顽固性心绞痛患者的临床症状,但是不能改善心肌缺血;PMR早期有心脏去神经作用,但是远期作用不显著。     

Catheter-based percutaneous myocardial laser revascularization in patients with end-stage coronary artery disease

OBJECTIVES: This study evaluates the feasibility and safety of a catheter-based laser system for percutaneous myocardial revascularization and analyses the first clinical acute and long-term results in patients with end-stage coronary artery disease (CAD) and severe angina pectoris. BACKGROUND: In patients with CAD and intractable angina who are not candidates for either coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA), transmyocardial laser revascularization (TMR) has been developed as a new treatment that results in reduced angina pectoris and increased exercise capacity. However, surgical thoracotomy is required for TMR with considerable morbidity and mortality. METHODS: A catheter-based system has been developed that allows creation of laser channels in the myocardium from within the left ventricular cavity. Laser energy generated by a Holmium: YAG (Cardiogenesis Corporation, Sunnyvale, California) laser was transmitted to the myocardium via a flexible optical fiber capped by an optic lens. The optical fiber was maneuvered to the target area under biplane fluoroscopy through a coaxial catheter system permitting movement in three dimensions. RESULTS: Thirty-four patients with severe CAD not amenable to either CABG or PTCA and refractory angina pectoris (Canadian Cardiologic Society [CCS] Angina Scale Class III-IV) were included in the study. Ischemic regions were identified by coronary angiography and confirmed by thallium scintigraphy. The percutaneous myocardial revascularization (PMR) procedure was successfully completed in all patients. In 29 patients, one vascular territory of the left ventricle and in 5 patients, two vascular territories were treated. Eight to fifteen channels were created in each ischemic region. Major periprocedural complications were limited to an episode of arterial bleeding requiring surgical repair. There was one death early after PMR, due to a myocardial infarction (MI) in a nontreated region. Clinical follow-up at 6 months (17 patients) demonstrated significant improvement of angina pectoris (CCS class before PMR: 3.0+/-0.0, six months after PMR: 1.3+/-0.8, p<0.0001) and increased exercise capacity (exercise time on standard bicycle ergometry before PMR: 384+/-141 s, six months after PMR: 514+/-158 s, p<0.05), but thallium scintigraphy failed to show improved perfusion of the laser treated regions. CONCLUSIONS: Percutaneous myocardial revascularization is a new safe and feasible therapeutic option in patients with CAD and severe angina pectoris not amenable to either CABG or PTCA. Initial results show immediate and significant improvement of symptoms and exercise capacity but evidence of improved myocardial perfusion is still lacking.     

Percutaneous myocardial laser revascularization (PMR)

In patients with severe angina pectoris due to coronary artery disease, who are not candidates for either percutaneous coronary angioplasty or coronary artery bypass surgery, transmyocardial laser revascularization (TMR) often leads to improvement of clinical symptoms and increased exercise capacity. One drawback of TMR is the need for surgical thoracotomy in order to gain access to the epicardial surface of the heart. Therefore, a catheter-based system has been developed, which allows creation of laser channels into the myocardium from the left ventricular cavity. Between January 1997 and November 1999, this "percutaneous myocardial laser revascularization" (PMR) has been performed in 101 patients at the Herzzentrum Leipzig. In 63 patients, only 1 region of the heart (anterior, lateral, inferior or septal) was treated with PMR, in 38 patients 2 or 3 regions were treated in 1 session. There were 12.3 +/- 4.5 (range 4 to 22) channels/region created into the myocardium. After 3 months, the majority of patients reported significant improvement of clinical symptoms (CCS class at baseline: 3.3 +/- 0.4, after 6 months: 1.6 +/- 0.8) (p < 0.001) and an increased exercise capacity (baseline: 397 +/- 125 s, after 6 months: 540 +/- 190 s) (p < 0.05). After 2 years, the majority of patients had experienced sustained clinical benefit after PMR, the CCS class after 2 years was 1.3 +/- 0.7, exercise capacity was 500 +/- 193 s. However, thallium scintigraphy failed to show increased perfusion in the PMR treated regions. The pathophysiologic mechanisms of myocardial laser revascularization is not yet understood. Most of the laser channels are found occluded after various time intervals after intervention. Other possible mechanisms include myocardial denervation or angioneogenesis after laser revascularization, however, unequivocal evidence for these theories is not yet available. In conclusion, PMR seems to be a safe and feasible new therapeutic option for patients with refractory angina pectoris due to end-stage coronary artery disease. The first results indicate improvement of clinical symptoms and increased exercise capacity, whereas evidence of increased perfusion after laser revascularization in the laser-treated regions is still lacking.     

Effect of spinal cord stimulation on regional myocardial perfusion assessed by positron emission tomography.

Spinal cord stimulation (SCS) can relieve symptoms in patients with severe angina pectoris refractory to conventional medical or surgical therapy. This symptomatic improvement may result from decreased myocardial ischemia. To test this hypothesis, positron emission tomography (PET) and potassium-38 as a flow tracer were used in 8 patients for the quantitative evaluation of regional myocardial perfusion at rest and after exercise, before and during SCS. Potassium uptake was evaluated as myocardial clearance (flow times net extraction) in ml/min/100 g. Tomographic segments were categorized as nonaffected and affected on the basis of the absence or presence of arterial stenosis on coronary angiography and on the basis of thallium scintigraphic data. In nonaffected segments, before SCS, regional myocardial clearance significantly increased from rest (28 +/- 4) to exercise (47 +/- 13 clearance units; p less than 0.004). A similar increase occurred after SCS. In affected segments, before SCS, regional myocardial clearance barely increased (p = 0.065) from rest (26 +/- 6) to exercise (33 less than or equal to 12). In comparison, after SCS, the resting regional myocardial clearance was slightly elevated (29 +/- 8) reflecting an increased double product, but did not increase (p = 0.192) with exercise (34 +/- 12). However, the magnitude and duration of ST-segment depression decreased during treatment with SCS. Anginal pain occurred in all patients during control exercise, but was attenuated in all but one with SCS. These results indicate that SCS improves exercise-induced angina and electrocardiographic signs of ischemia but this influence does not appear to be mediated by changes in regional myocardial perfusion.     

Absence of clinical signs of cardiac denervation after percutaneous myocardial laser revascularization

BACKGROUND: Percutaneous myocardial revascularization with laser (PMR) is a catheter-based technique that has generated much interest in the treatment of patients with severe coronary artery disease. Several mechanisms have been proposed to explain the reported clinical benefits of this technique. Cardiac autonomic denervation is among these. METHODS: We studied 32 consecutive patients with chronic severe angina not suitable for other revascularization approaches. Canadian Class Society (CCS) class clinical assessment, Naughton exercise stress test, and scintigraphic myocardial perfusion were evaluated before and 1 and 6 months after PMR. Ewing's autonomic tests, heart rate variability (HRV), and plasmatic catecholamines were assessed before revascularization in non-diabetic and diabetic patients and repeated 1 month after PMR in 13 non-diabetics. A psychological test was carried out before PMR to evaluate the attitude towards this new procedure. RESULTS: All the markers of autonomic cardiac control were unmodified after the procedure. Moreover, scintigraphic perfusion measured in the lasered areas was similar before and after the procedure. On the other hand, the clinical conditions significantly improved (CCS class from 3+/-0.8 to 1.9+/-0.9 at 1 month, P<0.01) and the exercise-related ischemic threshold was significantly better (from 311+/-28 to 453+/-51 s, P<0.05). The patients with a psychologically 'positive' expectation for this new procedure had results comparable to those with a 'negative' expectation. CONCLUSIONS: PMR improves symptoms in patients with end-stage coronary artery disease in the absence of any detectable clinical sign of heart denervation.     

Collateral formation in patients after percutaneous myocardial revascularization: a mechanism for improvement?

BACKGROUND: Percutaneous myocardial revascularization (PMR) has emerged as a novel therapeutic strategy for patients with ischemic heart disease not amendable to traditional revascularization approaches. Despite the symptomatic improvement documented in clinical trials, underlying mechanism remains unknown. METHODS: We assessed the coronary angiograms of 25 patients before and 6 months after the PMR procedures for collateral vessel formation. The Rentrop scoring system was used to score the extent of collateral vessel formation. The angiograms were analyzed by 2 independent reviewers. The change in Rentrop score and improvement in angina status was correlated. RESULTS: During follow-up period of 6 months, no patient died or suffered from myocardial infarction. Overall the mean Canadian Classification Society (CCS) class among the study patients was significantly improved from 3.5 to 2.4; mean difference = 1.08 (p < 0.0001). Among these, 8 (32%) had improvement of > 2 CCS classes (p = 0.003) (improvement group). The rest of the patients had either no change (n = 8; 32%) or improvement of 1 CCS class (n = 9; 36%) (no improvement group). The Rentrop score improved in 3 (12%), remained unchanged in 22 (88%) and deteriorated in 0 patient. Overall, there was no significant change in Rentrop score at 6-month follow-up; mean difference 0.13 (p = 0.08). There was also no correlation between the change in extent of collateral vessel formation and the improvement in angina status (correlation coefficient r = 0.09) at 6 months after PMR. CONCLUSION: Improvement in collateral vessel formation is unlikely to be a mechanism responsible for symptomatic improvement in patients after PMR.     

曲美他嗪对老年冠心病多枝病变患者不完全血运重建术预后的影响

目的:评价盐酸曲美他嗪对老年患者冠状动脉多枝病变行不完全血运重建术后疗效及预后的影响。方法:选取通过冠状动脉支架治疗术进行部分血运重建的老年患者73例,根据置入支架后服用曲美他嗪与否分为2组:盐酸曲美他嗪组(20 mg,3次/d,口服)38例,常规药物治疗组35例。统计所有患者随访12个月后心绞痛分级(CCS分级)、主要心脏不良事件(MACE)发生情况;并于开始服药治疗前以及服药12个月后,行超声心动图检查及6 min步行试验。结果:2组患者12个月的MACE发生率差异有统计学意义,盐酸曲美他嗪组:5.3%(2/38),常规治疗组:14.3%(5/35),P<0.05;盐酸曲美他嗪组患者的心绞痛发作例数、发作次数及心绞痛CCS级别等方面均优于常规治疗组(P<0.05)。治疗12个月后盐酸曲美他嗪组左心室射血分数(LVEF)较对照组改善,差异有统计学意义P<0.05;6min步行距离较常规治疗组明显增加(P<0.05)。结论:对于老年冠状动脉多枝病变患者行不完全血运重建术后,盐酸曲美他嗪可减少其术后心绞痛的发作,提高运动耐量,改善左心功能。     

Randomized comparative trial of a thin-strut bare metal cobalt-chromium stent versus a sirolimus-eluting stent for coronary revascularization.

OBJECTIVES: To see whether use of a sirolimus-eluting stent (SES) is superior to a third-generation thin-strut, cobalt-chromium stent (CCS) in terms of in-segment late loss at 9 months in patients with symptomatic coronary artery disease. BACKGROUND: Stent-strut thickness has been shown to be strictly related with risk of in-stent restenosis, but available demonstrations of the angiographic efficacy of SES have been based on comparisons with thick-strut bare metal control stents. METHODS: The primary outcome measure of this single-center, single-blind randomized comparative trial was 9-month in-segment late loss. Eligibility criteria were symptomatic coronary artery disease and target vessel diameter appropriate for implantation a 3-mm stent. Based on a power calculation, 104 patients were randomly assigned to receive a SES (Cypher) or a CCS (Vision). RESULTS: In-segment late loss was significantly lower in the SES group (0.18 +/- 0.40 mm vs 0.58 +/- 0.51 mm, P < 0.001). Regarding subsidiary outcome measures, in-segment restenosis (at 9 months) was recorded in 10% (5/50) patients treated with SES and 23% (11/48) receiving CCS (P = 0.14). No clinical difference between the two groups was apparent at 12 months. Freedom from target vessel failure at 12 months was 72% for SES patients and 68% for CCS patients (P = 0.65). CONCLUSIONS: In patients with de-novo coronary lesions at medium risk of restenosis the anti-proliferative effect of SES is greater than that of a thin-strut CCS. Nevertheless, the angiographic results of the CCS were rather good. It remains to be seen whether the angiographic superiority of SES can translate into clinical superiority.     

A randomized clinical trial of trimetazidine, a partial free fatty acid oxidation inhibitor, in patients with heart failure.

OBJECTIVES: This study sought to assess whether the long-term addition of trimetazidine to conventional treatment could improve functional class, exercise tolerance, and left ventricular function in patients with heart failure (HF). BACKGROUND: Previous small studies have shown that trimetazidine may be beneficial in terms of left ventricular function preservation and control of symptoms in patients with post-ischemic HF. METHODS: Fifty-five patients with HF were randomly allocated in an open-label fashion to either conventional therapy plus trimetazidine (20 mg three times daily) (28 patients) or conventional therapy alone (27 patients). Mean follow-up was 13 +/- 3 months. At study entry and at follow-up, all patients underwent exercise testing and two-dimensional echocardiography. Among the others, New York Heart Association (NYHA) functional class and ejection fraction (EF) were evaluated. RESULTS: In the trimetazidine group, NYHA functional class significantly improved compared with the conventional therapy group (p < 0.0001). Treatment with trimetazidine significantly decreased left ventricular end-systolic volume (from 98 +/- 36 ml to 81 +/- 27 ml, p = 0.04) and increased EF from 36 +/- 7% to 43 +/- 10% (p = 0.002). On the contrary, in the conventional therapy group, both left ventricular end-diastolic and -systolic volumes increased from 142 +/- 43 ml to 156 +/- 63 ml, p = 0.2, and from 86 +/- 34 ml to 104 +/- 52 ml, p = 0.1, respectively; accordingly, EF significantly decreased from 38 +/- 7% to 34 +/- 7% (p = 0.02). CONCLUSIONS: In conclusion, long-term trimetazidine improves functional class and left ventricular function in patients with HF. This benefit contrasts with the natural history of the disease, as shown by the decrease of EF in patients on standard HF therapy alone.     

Laser biostimulation in end-stage multivessel coronary artery disease--a preliminary observational study

BACKGROUND: Low-energy laser radiation through its direct influence on tissue repair processes without heating effect may have vital importance in the therapy of patients with advanced coronary artery disease (CAD). AIM: The introductory assessment of the effects of laser biostimulation applied to patients with advanced multivessel CAD. METHODS: 39 patients with advanced CAD were assigned (mean age 64.8+/-9.6, male gender 64%, CCS class 2.5+/-0.5, EF=46+/-11%, 69% with a history of acute myocardial infarction), to undergo two sessions of irradiation of low-energy laser light on skin in the chest area from helium-neon B1 lasers. The time of irradiation was 15 minutes while operations were performed 6 days a week for one month. Before including the patients in the experimental group a full clinical evaluation, basic biochemical tests, ECG, 24h Holter recordings, 6-minute walk test, treadmill test using Bruce protocol and full echocardiographic examination were performed. After the first and second period of laser therapy with a one-month break between them analogical parameters with the initial examination were measured. RESULTS: No side effects associated with the laser biostimulation or performed clinical tests were noted. Lower CCS class (2.5+/-0.5 --> 2.2+/-0.4 --> 2.0+/-0.4, p<0.001), higher exercise capacity (5.1+/-2.2 --> 5.8+/-2.2 --> 6.6+/-2.5 [METS], p=0.023), longer exercise time (257+/-126 --> 286+/-127 --> 325+/-156 [s], p=0.06), less frequent angina symptoms during the treadmill test (65% --> 44% --> 38%, p=0.02), longer distance of 6-minute walk test (341+/-93 --> 405+/-113 --> 450+/-109 [m], p <0.001), lower systolic blood pressure values (SP 130+/-14 --> 125+/-12 --> 124+/-14 [mmHg], p=0.05) and trend towards less frequent 1 mm ST depression lasting 1 min during Holter recordings were noted. CONCLUSIONS: An improvement of functional capacity and less frequent angina symptoms during exercise tests without a significant change in the left ventricular function were observed. Laser biostimulation in short-term observation was a very safe method. These encouraging results should be confirmed in a larger, placebo-controlled study.     

Prognostic significance of silent ischemia in the exercise test in patients with coronary disease

To evaluate the prognostic significance of silent ischemia during exercise testing, 152 consecutive patients (143 males, 9 females) with a mean SD of 55 +/- 7 years (age range 32-73) who underwent exercise testing and coronary arteriography within 3 months were studied. All patients had the following characteristics: 1) a positive electrocardiographic exercise test response; 2) significant coronary artery disease on the arteriography; 3) uninterrupted clinical follow-up for a minimum of 6 months. The 152 patients were divided in 2 groups: group I: 56 patients (37%) with ischemic ST-segment depression during exercise testing without angina (silent ischemia); group II: 96 patients (63%) with ischemic ST-segment depression and angina (symptomatic ischemia). Patients in group I and group II showed similar time to ST-segment depression (3.6 +/- 1.5 min vs 3.2 +/- 1.4 min; p = NS), maximal ST-segment depression and peak heart rate-systolic pressure product (21,151 +/- 7,124 vs 20,456 +/- 6,024; p = NS). Exercise duration was longer in group I than in group II (5.6 +/- 2.1 min vs 4.8 +/- 1.5 min; p less than 0.001). The extent of coronary artery disease defined by the number of significant narrowed coronary vessels, left ventricular end diastolic pressure and ejection fraction were similar in the 2 groups. Sixty six patients who underwent coronary bypass surgery were not included in the analysis. The remaining 86 patients (40 in group I and 46 in group II) were medically treated. The mean follow-up period was 43,5 +/- 25 months (range 6-101).2+ myocardial ischemia during exercise testing.     

Randomized trial of a medical food for the dietary management of chronic, stable angina.

OBJECTIVES: We determined the electrocardiographic, vascular and clinical effects of a medical food bar enriched with L-arginine and a combination of other nutrients known to enhance endothelium-derived nitric oxide (NO) in patients with stable angina. BACKGROUND: Enhancement of vascular NO by supplementation with L-arginine and other nutrients has been shown to have clinical benefits in patients with angina secondary to atherosclerotic coronary artery disease (CAD). However, the amounts and combinations of these nutrients required to achieve a clinical effect make traditional delivery by capsules and pills less suitable than alternative delivery methods such as a specially formulated nutrition bar. METHODS: Thirty-six stable outpatients with CAD and class II or III angina participated in a randomized, double-blind, placebo-controlled, crossover trial with two treatment periods each of two weeks' duration (two active bars or two placebo bars per day). Flow-mediated brachial artery dilation was measured by ultrasound. Electrocardiographic measures of ischemia, exercise capacity and angina onset time were measured by treadmill exercise testing and by Holter monitor during routine daily activities. Quality of life was assessed by SF-36 and Seattle Angina Questionnaires and by diary. RESULTS: The medical food improved flow-mediated vasodilation (from 5.5 +/- 4.5 to 8.0 +/- 4.9, p = 0.004), treadmill exercise time (by 20% over placebo, p = 0.05) and quality-of-life scores (SF-36 summary score; 68 +/- 13 vs. 63 +/- 21 after placebo, p = 0.04, Seattle Angina Questionnaire summary score; 67 +/- 10 vs. 62 +/- 18, p = 0.04) without affecting electrocardiographic manifestations of ischemia or angina onset time. CONCLUSIONS: These findings reveal that this arginine-rich medical food, when used as an adjunct to traditional therapy, improves vascular function, exercise capacity and aspects of quality of life in patients with stable angina.     

Percutaneous transmyocardial revascularization with holmium laser in patients with refractory angina: a pilot feasibility study.

BACKGROUND: Percutaneous transluminal myocardial revascularization (PTMR) is a new procedure to improve perfusion of the ventricular wall for patients with intractable angina that is untreatable by surgery or conventional catheter-based intervention. PTMR allows the creation of myocardial channels through the controlled delivery of holmium laser energy from the ventricular chamber. Preliminary studies in animals and human subject have yielded promising results. We now report the feasibility study of PTMR using a laser delivered through a novel Eclipse system, and we present the results of this sole therapy in patients with severe coronary disease and angina refractory to maximal medical treatment angina (III-IV CCS). METHODS: Percutaneous vascular access for PTMR treatment was obtained via the femoral artery. A 9F directional catheter carrying flexible fiber optics was used with a holmium laser (Eclipse system) and was placed across the aortic valve into the left ventricle cavity to create channels with a depth of 5 mm from the endocardial surface into the myocardial tissue. From April to November 1998, 15 patients underwent PTMR with Eclipse system. Two patients were female; the mean age was 66 +/- 8 (range 59-74). Five patients had a severe LV dysfunction (FE < 30%). Preoperative angina class was III in 10 patients and IV in 5 and previous myocardial procedures had been performed in all patients. RESULTS: The procedure was well tolerated and procedural success was obtained in 14 of 15 patients. There was one myocardial perforation because of guiding-catheter manipulation (pericardial drainage in fourth day). We performed a mean of 13 +/- 4 channels in a mean fluoro time of 23 +/- 11 min. Upon release and during follow-up (5.3 months +/- 4.2, range 2-10), angina class had significantly improved in 14 of 14 patients with complete PTMR treatment, with 4 asymptomatic patients, 6 patients in CCS I, 3 in CCS II, 2 in CCS III and only one patient hospitalized due to angina. CONCLUSION: This pilot study confirmed the safety and technical feasibility of PTMR. Immediate and short-term results confirm that a clinical improvement is obtained in most patients. Although these are early clinical benefits, the true efficacy of this approach will necessarily be defined by a randomized trials with prospectively-defined endpoints and with PTMR compared with medical therapy.     

曲美他嗪对冠状动脉介入术后患者心绞痛发作频率及运动耐量的影响

目的评价曲美他嗪对冠状动脉介入术后患者心绞痛发作频率及运动耐量的影响。方法首次冠状动脉介入治疗患者112例,分为曲美他嗪组以及常规治疗组,各56例。所有患者每月门诊随访1次,共6个月,记录心绞痛发作次数、每次发作持续时间、硝酸甘油的应用、心绞痛CCS分级,主要心脏不良事件(MACE)发生情况;并于开始治疗前以及药物治疗6个月后,行超声心动图检查及6min步行试验。结果两组患者MACE发生率差异无统计学意义(曲美他嗪组:8.9%,常规治疗组:10.7%)(P>0.05);在心绞痛发作例数、心绞痛发作次数、发作持续时间、心绞痛CCSⅢ级,发作时需用硝酸甘油缓解例数方面曲美他嗪组均少于常规治疗组(P均<0.05)。在治疗开始两组患者LVEF及6min步行距离差异无统计学意义(P均>0.05);治疗6个月后曲美他嗪组LVEF及6min步行距离较前显著改善(P均<0.05);且6min步行距离较常规治疗组明显增加(P<0.05)。结论冠状动脉介入术后常规加用曲美他嗪可以减少心绞痛发作,改善左心功能,提高运动耐量。     

Response of angina and ischemia to long-term treatment in patients with chronic stable angina: a double-blind randomized individualized dosing trial of nifedipine, propranolol and their combination.

Seventy-four patients with chronic stable mild angina, mild coronary artery disease (83% had one- or two-vessel disease) and normal left ventricular function were studied to measure the response of treadmill exercise performance and painful and silent ischemia in the ambulatory setting to randomly assigned treatment with nifedipine or propranolol and their combination; titration to maximal tolerated dosages was performed in double-blind manner. At 3 months both nifedipine and propranolol reduced the weekly angina rate (p less than 0.05); during treadmill exercise testing, increases (p less than 0.05) were noted in time to angina and total exercise time and decreases in maximal ST depression at the end of exercise. There were no differences between the responses to nifedipine and propranolol and no significant additional changes were seen after another 3 months of therapy. The combination of nifedipine and propranolol reduced the number of patients with angina on exercise treadmill testing from 64% to 38% (p less than 0.05). During ambulatory electrocardiographic monitoring before treatment, there were 1.4 +/- 2.4 (mean +/- SD) episodes/24 h of painful ischemia and a very low silent ischemia frequency: mean 1.1 +/- 2.7 episodes/24 h, mean duration 16 +/- 25 min/24 h. Treatment with propranolol and nifedipine resulted in reduction of episodes and duration of painful and painless ischemia; approximately 77% of patients were free of all ischemic episodes. It is concluded that patients with chronic stable mild angina have a low incidence of silent ischemia. Nifedipine or propranolol alone, titrated to individualized maximally tolerated dosages, are equally effective in long-term control of painful and painless ischemia, anginal episodes and exercise-induced ischemia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Stent implantation for the unprotected left main coronary artery. The long-term outcome of 62 patients

INTRODUCTION: Stent implantation for the unprotected left main coronary artery (ULMCA) is regarded as controversial and coronary heart disease with LMCA stenosis still remains a basic indication for bypass surgery. Although there is no doubt that the risk of stent implantation for LMCA lesions is low, there are still limited data on long-term outcomes. There have been no reports so far answering the question whether ULMCA stenting ensures adequate coronary blood flow in the vessel. AIM: Assessment of the effect of LMCA flow restoration with stenting on the coronary flow reserve assessed by an exercise test, as well as on left ventricular function and angina in patients followed for 12 months after the procedure. METHODS: The study population included 62 patients (17 women and 45 men) aged 61.4+/-11.1 (35-84 years) who underwent coronary angioplasty with elective ULMCA stenting. In all patients, serial echocardiography (before and 1, 3, 6, and 12 months after the procedure) and the exercise test according to the Bruce protocol (1, 3, 6, 12 months after the procedure) were carried out. Routine coronary angiography was performed 3 to 6 months after the procedure. Fifty-nine patients (95.2%) survived a 12-month period. In 24 (38.7%) patients major adverse cardiac events (MACE) occurred. In-stent restenosis was observed in 13 patients; in 11 of them repeated PCI was performed and 2 of them underwent CABG. One patient after repeated PCI required CABG. RESULTS: Severity of angina, evaluated according to the CCS scale, decreased significantly in the 12-month follow-up period as compared with the preprocedural period (p <0.00001). The mean baseline left ventricular ejection fraction was 51.6+/-12.5%. It increased to 53.8+/-12.8% (p <0.02) at 6 months and remained at this level at 12 months. The mean exercise test time was 7.0+/-3.4 minutes in the first month after ULMCA stenting, and in the sixth and the twelfth month of follow-up it increased to 7.6+/-3.4 minutes (p <0.002) and 7.8+/-3.2 minutes (p <0.05), respectively. The metabolic equivalent task (MET) value did not change significantly during the observation period. CONCLUSIONS: Restoration of the physiological blood flow in the unprotected left main coronary artery with stent implantation is associated with a significant reduction of angina, significant improvement of the left ventricular systolic function and preservation of exercise capacity in long-term follow-up.     

The immediate and long-term outcome of enhanced external counterpulsation in treatment of chronic stable refractory angina

BACKGROUND: Treatment of angina recalcitrant to conventional pharmacological therapy and revascularization remains problematic. Safe, effective and affordable treatments with high patient acceptability are desirable. Enhanced external counterpulsation (EECP) may fulfil these criteria better than many other proposed interventions. OBJECTIVE: To examine the immediate and long-term effect of EECP in treatment of chronic stable refractory angina. DESIGN: Prospective observational study of consecutive patients treated with EECP and follow-up for 1 year. SETTING: Teaching hospital. MAIN OUTCOME MEASURES: Canadian Cardiovascular Society (CCS) angina grading, weekly angina frequency and glyceryl trinitrate (GTN) use. RESULTS: Sixty-one patients were treated with EECP and 58 completed a course of treatment. Further analysis is confined to those who completed EECP. About 52% of patients suffered from CCS III and IV angina prior to EECP. Immediately post-EECP, angina improved by at least one CCS class in 86% and by two classes in 59%. At 1-year follow-up, sustained improvement in CCS was observed in 78% of the patients. The median weekly angina frequency and GTN use were significantly reduced immediately after EECP [7 (4-14) vs. 1 (0-4) episodes per week and 7 (2-16) vs. 0 (0-2) times per week respectively, P < 0.0001; data in median (interquartile range)]. The reduction was sustained at 1-year follow-up. In 48 patients, their mean exercise time improved significantly after EECP [301 +/- 130 s vs. 379 +/- 147 s, P < 0.0001]. Major adverse treatment-related events were rare. CONCLUSION: This study shows that for patients who fail to respond to conventional measures, a high proportion gain symptomatic benefit from EECP.     

Late intervention after anterior myocardial infarction: effects on left ventricular size,function, quality of life,and exercise tolerance: results of the Open Artery Trial (TOAT Study)

OBJECTIVE: We sought to conduct a randomized trial comparing late revascularization with conservative therapy in symptom-free patients after acute myocardial infarction (AMI). BACKGROUND: In the absence of ischemia, the benefits of reperfusion late after AMI remain controversial. However, the possibility exists that an open infarct related artery benefits healing post AMI. METHODS: Of 223 patients enrolled with Q-wave anterior AMI, 66 with isolated persistent occlusion of the left anterior descending coronary artery (LAD) were randomized to the following treatments: 1) medical therapy (closed artery group; n = 34) or 2) late intervention and stent to the LAD + medical therapy (open artery group; n = 32). The study was powered to compare left ventricular (LV) end-systolic volume between the two groups 12 months post AMI. RESULTS: Late intervention 26 +/- 18 days post AMI resulted in significantly greater LV end-systolic and end-diastolic volumes at 12 months than medical therapy alone (106.6 +/- 37.5 ml vs. 79.7 +/- 34.4 ml, p < 0.01 and 162.0 +/- 51.4 ml vs. 130.1 +/- 46.1 ml, p < 0.01, respectively). Exercise duration and peak workload significantly increased in both groups from 6 weeks to 12 months post AMI, although absolute values were greater in the open artery group. Quality of life scores tended to deteriorate during this time interval in the closed artery patients but remained unchanged in the open artery patients. Coronary angiography at 1 year documented a low incidence of intergroup cross-over (spontaneous recanalization in 19% and closure in 11%). CONCLUSIONS: In the present study, recanalization of occluded infarct-related arteries in symptom-free patients approximately 1 month post AMI had an adverse effect on remodeling but tended to increase exercise tolerance and improve quality of life.     

Usefulness of dobutamine in producing myocardial ischemia. Comparison with ergometry

Fifty six patients were studied while in the Coronary Care Unit: 17 with unstable angina and 39 with acute myocardial infarction. All patients underwent dobutamine stress testing (doses of 5, 10, 15 and 20 micrograms/kg/min every 5 min) and exercise testing (modified protocol to finish at an energy expenditure of approximately 5 METS): 4-5 days after the last crisis of angina or 6-8 days after the onset of noncomplicated acute myocardial infarction. The heart rate increased from 72 +/- 10 to 104 +/- 12 beat/min with dobutamine (p = 0.00001) and from 84 +/- 11 to 118 +/- 15 beat/min with exercise testing (p = 0.00001). The systolic blood pressure increased from 116 +/- 9 to 138 +/- 11 mmHg with dobutamine (p = 0.00001) and from 117 +/- 8 to 156 +/- 7 mmHg with exercise testing (p = 0.00001). Due to different reasons 33 patients did not finish the exercise protocol, while only 8 patients did not finish the dobutamine testing. The ST segment wast elevated in 22 cases with dobutamine and in 9 cases with exercise, eight of them coinciding in both tests. The ST segment was depressed in 36 cases with dobutamine and in 21 cases with exercise, 20 of them coinciding in both tests. Angina was present in 11 cases with dobutamine and in four exercise, three of them coinciding. If the unfinished tests or those with angina or ST segment depression are considered abnormal, there were 40 abnormal tests with dobutamine and 38 with exercise, 32 of them coinciding.(ABSTRACT TRUNCATED AT 250 WORDS)     

Troponin T--is it a marker of restenosis after transluminal percutaneous angioplasty in unstable angina patients?

Troponin T (TpT) is a protein implicated in skeletal muscle contractions, including myocardium. It was shown that the presence of troponin TpT in unstable angina patients' blood is associated with poor prognosis. In the present study amongst 25 patients with unstable angina 12 were found to have TpT present in their blood. TpT concentration was higher in patients with III and IVo CCS symptoms in comparison with class I and IIo CCS symptoms: 0.207 +/- 0.275 and 0.144 +/- 0.186 ng/mL respectively (p = 0.053; nonparametric Kolmogorow-Smirnov test). Patients were subjected to percutaneous transluminal coronary angioplasty (PTCA). After 3 months of follow up 17 patients (the rest of them dropped out) were assigned to two groups: A (n = 8)--without and B (n = 9)--with clinical and electrocardiographic signs of restenosis. Retrospective analysis revealed the presence of TpT before PTCA in 6 group B patients and 2 group A patients. Relative risk of stenocardia recurrence was calculated as 2.25. TpT was present in the blood of 20 patients in the first 24 hours after PTCA, and group B patients had higher mean TpT concentration; that could result from reperfusion of more ischaemic myocardium. It seems that the presence of TpT in unstable angina patients' blood may be an important factor characterizing patients with more serious prognosis.