Relation between exertional ischemia and prognosis in mildly symptomatic patients with single or double vessel coronary artery disease and left ventricular dysfunction at rest

The randomized multicenter trials indicate that survival in patients with coronary artery disease and left ventricular dysfunction is enhanced by surgical therapy compared with medical therapy. This beneficial effect of coronary bypass surgery was demonstrated in patients with either three vessel or left main coronary artery disease, but not in those with one or two vessel disease. To determine whether subgroups of mildly symptomatic patients with one or two vessel coronary artery disease and left ventricular dysfunction have an increased risk of death or cardiac events during medical therapy, 53 consecutive patients with angiographically defined one or two vessel disease and impaired left ventricular function (ejection fraction 20% to 40%) were studied by exercise electrocardiography (ECG) and rest and exercise radionuclide angiography. All but two patients had previous myocardial infarction, and all were asymptomatic or only mildly symptomatic during medical therapy. By univariate life table analysis, mortality during medical therapy was associated significantly with the ST segment response to exercise (p less than 0.05) and with both the exercise ejection fraction (p less than 0.05) and the magnitude of change in ejection fraction with exercise (p less than 0.005). In patients with an exercise ejection fraction greater than 30%, the probability of survival at 6 years was 97 +/- 3% (+/- SE) compared with a survival rate of 62 +/- 14% in the remaining subjects (p less than 0.005). Similarly, 6 year survival was 100% in patients whose ejection fraction increased from the value at rest but was only 74 +/- 10% in the remaining patients (p less than 0.005). Exercise capacity was not associated with survival.(ABSTRACT TRUNCATED AT 250 WORDS)     

Determinants of exercise-induced changes in mitral regurgitation in patients with coronary artery disease and left ventricular dysfunction

OBJECTIVES: We sought to examine the determinants of exercise-induced changes in ischemic mitral regurgitation (MR) in patients with left ventricular (LV) dysfunction. BACKGROUND: In the post-myocardial infarction (MI) phase, ischemic MR contributes to worsening of symptoms and of LV dysfunction. METHODS: In this study, 70 patients in the chronic, post-MI phase, with LV ejection fraction <45% and at least mild MR, underwent semi-supine exercise Doppler echocardiography. The effective regurgitant orifice (ERO) of MR was quantified at rest and during exercise. Exercise-induced changes in ERO were compared with changes in mitral deformation and in local and global LV remodeling. RESULTS: The wide range of exercise-induced ERO changes that were observed was unrelated to the degree of MR at rest (r = 0.20). Effective regurgitant orifice changes correlated best with changes in mitral deformation (i.e., differences in systolic mitral tenting area, systolic annular area, and coaptation height) (p < 0.0001). Posterior displacement of the papillary muscles was associated with larger changes in the ERO in both infarct groups. In patients with inferior MI, a decrease in the ERO was related to improvement in wall motion (r = 0.68). The independent predictors of ERO changes during exercise were changes in systolic annular area for all infarct categories, in tenting area and wall motion score in the global population and those with inferior infarction, and in apical displacement of mitral leaflets for patients with anterior MI. CONCLUSIONS: The degree of MR at rest is unrelated to exercise-induced changes in EROs, which are related to those in local LV remodeling and in mitral deformation but not those in global LV function.     

Determinants of survival in patients with malignant ventricular arrhythmia associated with coronary artery disease

The long-term survival data in patients with coronary artery disease and a history of malignant ventricular arrhythmia, defined as noninfarction ventricular fibrillation (VF) or hemodynamically compromising ventricular tachycardia (VT) followed for up to 9 years, were analyzed. In this group of 161 patients there was a total of 57 deaths, of which 35 (63%) were sudden. Life-table analysis demonstrated a 10% sudden death rate for all patients in the first year and a 7% annual rate in the subsequent 4 years. In patients managed noninvasively, the overall mortality rate was 27% over 9 years, or 3% per year. Suppression of ventricular tachycardia on both ambulatory monitoring and exercise testing was associated with improved survival. In patients evaluated by electrophysiologic testing the sudden death rate was 1.4% per year over an average of 5 years. This survival rate was not different compared with the noninvasive group (p = 0.09). Measures of left ventricular dysfunction and the frequency of ventricular arrhythmia before and after drug therapy were associated with a risk of sudden cardiac death by univariate analysis. Multivariate regression analysis identified 4 variables as independent predictors of sudden cardiac death: rales (p = 0.009), the number of runs of VT during exercise testing while receiving antiarrhythmic drug therapy (p = 0.0003), a history of congestive heart failure (p = 0.0009) and the number of premature beats on Holter monitoring (p = 0.01). These findings support the concept that suppression of repetitive arrhythmia on Holter monitor and exercise testing is a marker for improved survival among patients with malignant ventricular arrhythmia.(ABSTRACT TRUNCATED AT 250 WORDS)     

Prognosis of asymptomatic or mildly symptomatic patients with coronary artery disease

One hundred forty-seven asymptomatic or mildly symptomatic patients with coronary artery disease, who did not have significant left main coronary occlusion and had an ejection fraction greater than 20 percent, were followed up prospectively for 6 to 67 months (average 25). Significant obstruction of one coronary artery was present in 28 percent of patients, of two coronary arteries in 31 percent and of three coronary arteries in 41 percent. Ejection fraction was 55 percent or greater in 69 percent of patients. During the follow-up period there were eight deaths (annual mortality rate 3 percent for the entire group, 1.5 percent for patients with single and double vessel disease but 6 percent for those with triple vessel disease). Better definition of high and low risk subgroups of patients with three vessel disease was accomplished with exercise testing. Despite a history of mild symptoms, 25 percent of the patients with triple vessel disease exhibited poor exercise capacity on exercise testing after administration of beta adrenoceptor blocking agents and nitrates was discontinued; of these, 40 percent either died (20 percent) or had progressive symptoms requiring operation (20 percent) (annual mortality rate 9 percent). Of the patients with good exercise capacity, only 22 percent either died (7 percent) or had progressive symptoms (15 percent) (annual mortality rate 4 percent).

Thus, prognosis is excellent in patients with no or mild symptoms who have one or two vessel coronary disease. Patients with three vessel disease who have good exercise capacity documented by objective testing have an annual mortality rate of 4 percent. However, because patients with three vessel disease and poor exercise capacity have an extremely grave prognosis, it would appear reasonable to recommend coronary bypass surgery for this subgroup, even in the absence of supporting data derived from a definitive randomized study.     

Revascularization for patients with severe coronary artery disease and left ventricular dysfunction

Heart failure is becoming increasingly prevalent, and currently coronary artery disease (CAD) is the primary cause of left ventricular (LV) systolic dysfunction. A potential therapeutic option for patients with severe CAD and LV dysfunction is a strategy of revascularization. In this review, we summarize the available literature regarding revascularization for these patients. The literature suggests that patients with severe CAD and LV dysfunction may benefit from revascularization and those patients with viable myocardium may derive the most benefit.     

Impaired maximal rate of left ventricular relaxation in patients with coronary artery disease and left ventricular dysfunction.

It has been suggested that the rate of left ventricular (LV) relaxation is related to the inotropic state, end-systolic fiber length and peak LV pressure, but little information is available regarding the rate of LV relaxation in patients with coronary artery disease (CAD) and LV dysfunction. To assess the rate of LV relaxation we obtained high-fidelity LV pressure measurements with manometer-tip catheters in 39 patients. The signal was analyzed by a digital computer to yield the maximal rate of pressure rise (pos dP/dt) and the maximal rate of pressure fall (neg dP/dt). Selective coronary arteriography and biplane LV angiography with determination of LV volumes, ejection fraction (EF) and percent abnormally contracting segments (ACS) when present, were performed in all patients. In 10 patients with normal LV function (EF greater than 0.50, no asynergy) mean neg dP/dt (2074 +/- 121 mm Hg/sec) was significantly (p less than 0.01) greater than in 29 patients with CAD and LV dysfunction (1695 +/- 66 mm Hg/sec). In nine patients with LV dysfunction and EF less than 0.35, mean neg dP/dt was reduced to 1405 +/- 107 mm Hg/sec, significantly (p less than 0.01) lower than in patients with normal LV function. Neg dP/dt correlated well with pos dP/dt (r = 0.75), with EF (r = 0.74), and with ACS (r = -0.74), and less well with LV end-systolic volume (r = 0.67). There was very poor correlation between neg dP/dt and peak LV pressure (r = 0.30). These data suggest that the rate of LV relaxation, as assessed by neg dP/dt, is impaired in patients with CAD and LV dysfunction, and the extent of impairment is related to the severity of the dysfunction as determined hemodynamically by pos dP/dt, and angiographically by EF and ACS. In these patients the maximal rate of LV relaxation is inversely related to LV end-systolic volume, and is not related to peak LV pressure.     

冠状动脉病变与左室功能的关系

目的:探讨冠状动脉(冠脉)病变患者的冠脉病变程度与左心室功能的关系。方法:对127例冠脉造影确诊的,至少存在一支病变狭窄程度大于75%的冠心病患者的心功能进行分析,并比较经皮冠脉介入治疗(PCI)患者治疗前后心功能的改变,以循证冠脉病变与左心室功能之间的相互关系。结果:冠脉病变愈严重,则其心功能损失愈大(P<0.001)。就收缩功能而言,冠脉单支病变者与双支病变者间变化无显著差异,单支、双支病变心功能显著好于三支病变(P<0.01);而舒张功能改变在单支、双支病变间即存在显著差异(P<0.05),但在双支病变与三支病变者间则无显著差异。冠脉病变部位与心功能亦有关系,以前降支病变者心功能损失最大(P<0.01)。其心功能于PCI后有显着改善(P<0.05～<0.001)。结论:冠脉病变程度及部位与左心室功能有关,PCI可改善患者的心功能。     

冠状动脉粥样硬化性心脏病伴左心功能不全高危患者的外科治疗

目的总结分析冠状动脉粥样硬化性心脏病（冠心病）伴左心功能不全高危患者行外科治疗的疗效。方法回顾性分析29例高危冠心病伴左心功能不全患者（年龄〉70岁）外科治疗的临床资料,着重分析手术方法和疗效。结果围手术期死亡5例（17.2%,5/29）,均死于严重低心排血量综合征。超声心动图复查示术后左心室舒张期末内径与术前比较明显减小,差异有统计学意义[（54.71±4.91）mm vs.（58.33±3.46）mm,t=3.2442,P〈0.05];左心室射血分数较术前明显提高（45.36%±10.27%vs.32.86%±4.10%,t=6.0873,P〈0.05）。结论对于高龄伴左心功能不全冠心病患者行外科治疗,其手术时机和手术方式的合理选择,围手术期的积极治疗能明显提高术后生存率。     

血运重建对冠心病合并心功能不全患者心肌收缩功能和心室重构的影响

目的探讨血运重建对冠心病合并左心功能不全患者心肌收缩功能和心室重构的影响。方法86例冠心病合并心功能不全患者术前应用超声心动图进行心功能、左心室(左室)几何形态和心肌活性评定,分为有存活心肌组和无存活心肌组,两组分别行血运重建或药物治疗。随访(13±5)个月后重新评价上述指标。结果57例有存活心肌的患者中行血运重建者较药物治疗者左室射血分数(LVEF)、存活节段数、左室球状指数(LVSI)明显提高;左室舒张末容积(LVEDV)、左室收缩末容积(LVESV)、左室重量(LVM)明显降低(P值均<0.01)。29例无存活心肌的患者中上述指标两种治疗间无显著性差异(P值均>0.05)。结论血运重建能改善冠心病合并左心功能不全但有存活心肌患者的心肌收缩功能和几何形态。     

Transient left ventricular dysfunction during provocative mental stress in patients with coronary artery disease

We studied the temporal effects of various types of mental stress and physical exercise on the left ventricular ejection fraction (LVEF) in seven normal volunteers and nine patients with coronary artery disease. Three types of psychological stress were administered: mental arithmetic, the Stroop color word test, and a personally relevant speaking task. In the normal volunteers the LVEF response was either flat or increased (p less than 0.05) compared to the baseline value during the mental tasks and increased by a mean of 10 +/- 5% (p less than 0.05) during exercise. In contrast, in patients with coronary disease in whom LVEF did not increase greater than or equal to 5% during exercise, LVEF decreased significantly during the mental tasks (p less than 0.05 for arithmetic and Stroop tasks). Typically LVEF decreased quickly during mental stress with an immediate rebound after intervention. Decreases in LVEF during mental stress occurred without chest pain and were not associated with ECG changes. In patients with coronary disease in whom LVEF increased normally with exercise (LVEF increase greater than or equal to 5%), no significant changes in LVEF occurred during mental stress. The heart rate x systolic blood pressure double product during mental stress was significantly less than that achieved during exercise (p less than 0.05) in each normal subject and patient. Thus psychological stress can provoke acute decreases in LVEF in patients with coronary disease and exercise-inducible dysfunction. The silent nature of the mental stress-induced abnormalities and their occurrence at a lower physiologic workload compared to abnormalities during exercise parallel characteristics of transient ischemia noted during ambulatory monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)     

Predictors of right ventricular dysfunction in patients with coronary artery disease and reduced left ventricular ejection fraction

BACKGROUND: The frequency and determinants of right ventricular (RV) dysfunction in patients with coronary artery disease (CAD) and reduced left ventricular (LV) function have not been thoroughly investigated. METHODS: The study population consists of 80 consecutive patients, invasively evaluated at our centre. Entry criteria were: LV ejection fraction < 45%; angiographic evidence of obstructive CAD; disease history of more than 3 months' duration. Exclusion criteria were: recent myocardial infarction and unstable angina. All patients underwent cardiac catheterization with coronary, LV and RV angiography. RV dysfunction was defined as a RV ejection fraction < 35%, which corresponds to the mean-three standard deviations of controls. RESULTS: Sixty-five patients (81%) had multi-vessel disease and 57 (71%) had a previous myocardial infarction. Mean LV ejection fraction was 31 +/- 8%. Mean RV ejection fraction was 46 +/- 11%. Right ventricular dysfunction was present in 14 patients (18%). An occluded proximal right coronary artery was associated with significantly lower RV ejection fraction (38 +/- 12% versus 47 +/- 10%; P = 0.009) but not LV ejection fraction (30 +/- 8% versus 32 +/- 9%; P = 0.444). However, at multivariate analysis, only pulmonary hypertension was an independent significant predictor of RV dysfunction (P < 0.001; OR: 1.13; CI: 1.06 -1.22). CONCLUSION: Right ventricular dysfunction in patients with chronic ischaemic LV dysfunction is detected in less than 20% of cases. Proximal right coronary artery occlusion is associated with a reduced RV ejection fraction. However, the role of right coronary artery disease is overwhelmed by the haemodynamic burden of pulmonary hypertension, which represents the only independent predictor of RV dysfunction in our population.     

Mental stress-induced myocardial ischemia in coronary artery disease patients with left ventricular dysfunction.

BACKGROUND: Reduced left ventricular ejection fraction (LVEF) is a risk factor for poor outcomes in patients with coronary artery disease (CAD). Mental stress-induced myocardial ischemia (MSIMI) also identifies a subset of CAD patients at increased risk for future cardiovascular events. Susceptibility to MSIMI in patients with CAD and reduced LVEF is unknown. METHODS AND RESULTS: We enrolled 182 patients (67 women) with a mean age of 64 years and a documented history of CAD in this study. Baseline resting ejection fraction was determined by use of technetium 99m sestamibi gated single photon emission computed tomography. Abnormal LVEF was defined as less than 45% for men and less than 50% for women (based on published norms for our software [Cedars-Sinai Medical Center]). All participants underwent mental stress testing with a public speaking task. Rest/stress myocardial perfusion single photon emission computed tomography was performed via conventional methodology. Images were visually compared for number and severity of perfusion defects by use of a scoring method from 0 to 4. A summed difference score was calculated as the difference between summed stress and rest scores. A score of greater than 3 was considered abnormal. MSIMI developed in 19% of patients with normal LVEF and 31% of those with reduced LVEF. There is no statistically significant difference between the two groups (P = .11). CONCLUSIONS: CAD patients with left ventricular dysfunction are equally susceptible to MSIMI as those with normal LVEF.     

Ventricular arrhythmias in hypertensive left ventricular hypertrophy. Relationship to coronary artery disease, left ventricular dysfunction, and myocardial fibrosis

Ventricular arrhythmias occur with increased frequency in hypertensive patients with left ventricular hypertrophy (LVH). The relationships, however, between ventricular arrhythmias and coexistent coronary artery disease, left ventricular dysfunction and left ventricular fibrosis have not been examined in hypertensive LVH. We carried out coronary arteriography on fifteen hypertensive patients with LVH and nonsustained ventricular tachycardia (greater than or equal to 3 consecutive ventricular complexes) of whom nine (60%) were free of significant (greater than 50% stenosis) coronary disease. To identify other possible correlates of left ventricular arrhythmias, 28 patients with LVH, comprising 17 with ventricular tachycardia and 11 without ventricular arrhythmias, underwent quantitative assessment of left ventricular function (angiographic ejection fraction), left ventricular mass (echocardiography), and left ventricular fibrosis (endomyocardial biopsy). Ejection fraction was not significantly different between the two groups (53 +/- 8% v 62 +/- 2%, P = NS). However, left ventricular mass was significantly greater (442 +/- 28 g v 339 +/- 34 g, P less than .05) and percentage fibrosis significantly higher (19 +/- 4% v 3 +/- 1%, P less than .001) in those patients with ventricular tachycardia. Thus ventricular arrhythmias in hypertensive patients with LVH cannot be entirely attributed to coexistent coronary disease, nor to left ventricular dysfunction, but are related to the degree of cardiac hypertrophy and subendocardial fibrosis.     

Predictors of rapid QRS widening in patients with coronary artery disease and left ventricular dysfunction

To assess the predictors of rapid QRS widening in patients with chronic ischemic left ventricular dysfunction, 82 patients who underwent > or =2 electrocardiograms and exercise Doppler echocardiography were studied. In a multivariate analysis, left ventricular end-diastolic volume, a large increase in mitral regurgitant volume during exercise, and diabetes emerged as independent predictors of QRS widening.     

Impact of left ventricular hypertrophy on ventricular arrhythmias in the absence of coronary artery disease

Left ventricular hypertrophy has a grave prognosis. Ventricular arrhythmias may account for a large portion of this poor prognosis, but the contribution of coronary artery disease has not been excluded. The occurrence of ventricular arrhythmias was investigated by 24 h ambulatory electrocardiographic (ECG) monitoring in 49 hypertensive patients who had normal findings on coronary arteriography. The presence of left ventricular hypertrophy was assessed by both ECG and echocardiography. The frequency and complexity of ventricular arrhythmias were significantly related to the presence of left ventricular hypertrophy whether it was defined by wall thickness (interventricular septum or posterior wall greater than or equal to 1.2 cm) or by left ventricular mass indexed to height (left ventricular mass/height greater than or equal to 163 g/m in men and greater than or equal to 121 g/m in women). The relation between left ventricular mass or wall thickness to ventricular arrhythmia was graded and continuous; for every 1 mm increase in the thickness of interventricular septum or posterior wall there was an associated two- to threefold increase, respectively, in the occurrence and complexity of ventricular arrhythmias. In conclusion, left ventricular hypertrophy is associated with an increase in the frequency and complexity of ventricular arrhythmias in the absence of coronary artery disease, and the relation is graded and continuous.     

Relation between spontaneous and electrically inducible ventricular arrhythmias in patients with coronary heart disease

In a prospective study, 267 patients with invasively diagnosed coronary artery disease were studied by programmed electrical stimulation (PES) and induced ventricular arrhythmias were compared to spontaneous arrhythmias occurring during 24 h Holter registration. In 89 patients (33%) no evidence of myocardial infarction was present, 61 patients (23%) were studied for 6 weeks to 3 months, 36 patients (13%) for 3-6 months and 81 patients (31%) for more than 6 months after myocardial infarction. PES was performed in the right ventricular apex with 1 and 2 extrastimuli during pacing with 100, 120 and 140 beats/min. Endpoint of the study was defined by the induction of 4 repetitive ventricular responses (RVR). Within 72 hours after PES a 24 h Holter registration was performed in all patients. During PES, 15 patients (6%) were not inducible for any RVR. Single RVR (1-2) were induced in 146 patients (55%) and 3-5 RVR in 68 patients (25%). Ventricular tachycardia and ventricular fibrillation were induced in 38 patients (14%); 6 patients showed a sustained, monomorphic tachycardia. Altogether, the incidence of RVR was higher when a history of myocardial infarction was present. With increasing time after infarction the incidence of inducible 3-5 RVR remained stable; however, the number of greater than 6 RVR decreased. During Holter registration, 54/255 patients (21%) showed no spontaneous ventricular arrhythmias, 70 patients (28%) had arrhythmias of Lown-class I/II, 84 patients (33%) of Lown-class III. Complex arrhythmias were observed in 47 patients (18%) (Lown-class IVA: 33 patients, IVB: 14 patients).(ABSTRACT TRUNCATED AT 400 WORDS)     

Association of obesity with left ventricular remodeling and diastolic dysfunction in patients without coronary artery disease

Obese patients frequently complain of dyspnea. Deconditioning and altered left ventricular (LV) systolic or diastolic function with elevated filling pressures may contribute to dyspnea. This study analyzed 4,281 patients who underwent diagnostic coronary angiography from January 1, 1995, to December 31, 2000. No patients had coronary artery stenoses >50% of the luminal diameter, and all underwent echocardiography within the same 6-year period. The association between body mass index (BMI) and LV structure and systolic and diastolic function was examined. All analyses controlled for age and gender, with the effect size for BMI expressed using a standardized coefficient (SC). A higher BMI was associated with greater LV mass (SC 0.18, p <0.001), wall thickness (SC 0.17, p <0.001), and end-diastolic diameter (SC 0.07, p <0.001). Stroke volume increased with a higher BMI (SC 0.12, p = 0.001), but there was no association between BMI and the ejection fraction (SC 0.003, p = 0.81). Hemodynamic data from invasive studies showed an association between a higher BMI and increased LV end-diastolic pressure (mean 17 mm Hg for BMI <25 kg/m(2) vs 24 mm Hg for BMI >or=40 kg/m(2); SC 0.18, p <0.001), which persisted after controlling for end-diastolic volume (SC 0.22, p <0.001). Obesity was associated with ventricular remodeling, which may normalize wall stress while increasing stroke volume to match metabolic demand. Obesity was not associated with decreased systolic function. However, obesity was associated with increased LV end-diastolic pressure, which suggests an association between obesity and diastolic dysfunction. In conclusion, ventricular remodeling, LV diastolic dysfunction, and elevated filling pressures may contribute to the prevalence of heart failure in obese patients.     

Predictors of ventricular dysfunction and coronary artery disease in Iranian patients with left bundle branch block

Patients with coronary artery disease (CAD) and concomitant left bundle branch block (LBBB) have increased cardiovascular mortality rates in comparison with those with CAD but without LBBB. In patients with LBBB, therefore, the delineation of the presence and severity of CAD may be helpful in providing prognostic information. In this cross-sectional study 219 patients with LBBB and suspected CAD that underwent coronary angiography, assessed for having CAD and left ventricular (LV) dysfunction. CAD was present in 124 (56.3%) patients and left ventricular ejection fraction <50% was seen in 147 (67.1%) patients. Advanced age (p=0.001), male gender (p=0.027, OR=1.94), history of chest pain (p=0.015, OR=2.08) and LVEF <50% (p=0.026, OR=3.04) were predictors of CAD and older age (p=0.004), male gender (p=0.017, OR=2.11), history of diabetes mellitus (p=0.043, OR=1.45) and angiographically documented CAD (p=0.001, OR=3.41) were predictors of LV dysfunction.