Effect of recanalization of chronic total occlusions on global and regional left ventricular function in patients with or without previous myocardial infarction.

Previous studies have demonstrated improvement of regional wall motion and global left ventricular function after successful recanalization of chronic total occlusion in coronary artery. However, the difference of benefits of recanalization between infarct site and noninfarct site is unknown. This study assessed the changes in left ventricular ejection fraction, regional wall motion after successful angioplasty of chronic total occlusions with or without previous myocardial infarction. This study also evaluated the factors that influenced the outcome of left ventricular function. We retrospectively studied 75 patients with a successfully recanalized chronic total occlusion in native coronary artery. Left ventriculograms were obtained at baseline and after 6 months. Global and regional left ventricular function were determined. The patients were divided into two groups. Group 1 comprised patients without previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Group 2 comprised patients with previous myocardial infarction in the territories of total occlusion vessel that was recanalized. Left ventricular ejection fraction increased from 53.2% +/- 16.3% at baseline to 57.3% +/- 20.1% at 6-month follow-up in the whole group (P = 0.001). In group 1 patients, the evolution of left ventricular (LV) ejection fraction increased from 59.5% +/- 13.7% to 67.3% +/- 14.6% (P < 0.001). In group 2 patients, the evolution of LV ejection fraction increased, but not significantly, from 48.9% +/- 16.2% to 50.5% +/- 16.9% (P = NS). The evolution of LV ejection fraction increased from 47.6% +/- 17.4% to 50.8% +/- 17.5% (P < 0.05) in the subgroup of recanalization in infarct-related vessel that had rich collateral circulation and had long-term patency. The regional wall motion all significantly improved in group 1 patients (P < 0.05). The regional wall motion did not change in group 2 patients (P = NS). The influence of recanalization of chronic coronary occlusions on the improvement of left ventricular global function was different between myocardial infarction and nonmyocardial infarction patients. The left ventricular function did not improve in myocardial infarction patient. Regional wall motion improved in patients without previous myocardial infarction. For reliable improvement of left ventricular function after recanalization of chronic total occlusions, evidence (not only by symptom or treadmill test) of viable myocardium in recanalized vessel is important. It is also important to keep patency of infarct-related vessel that has good collateral circulation for improving the left ventricular function.     

The effect of coronary artery bypass grafting on left ventricular systolic function at rest: evidence for preoperative subclinical myocardial ischemia

Successful coronary artery bypass grafting (CABG) improves exercise-induced left ventricular (LV) dysfunction in patients with coronary artery disease (CAD), but its potential for improving resting LV function remains controversial. To assess the influence of CABG on LV function at rest, 31 CAD patients without previous myocardial infarction were studied before and 6 months after CABG by radionuclide angiography after all cardiac medicines were withdrawn. No patient had angina or ischemic electrocardiographic changes at rest. In 27 patients with patent bypass grafts, CABG significantly increased LV ejection fraction during exercise (47 +/- 11% before to 63 +/- 9% after operation, p less than 0.001), indicating reduction in exercise-induced LV ischemia. Moreover, LV ejection fraction at rest also increased (55 +/- 9 to 60 +/- 8%, p less than 0.001), with 20 of 27 patients manifesting an increase compared with preoperative values. Eleven of these 20 patients had apparently normal LV function at rest (ejection fraction and regional wall motion) before CABG. LV regional ejection fraction was computed by dividing the LV region of interest into 20 sectors. Regional analysis indicated that improved ejection fraction at rest after CABG occurred in regions developing ischemia during exercise before CABG. In 4 patients with occluded grafts, the ejection fraction at rest was unchanged by CABG globally (59 +/- 8 to 58 +/- 9%, difference not significant) and regionally. Thus, LV global and regional function at rest improved after successful CABG, even in patients with normal global LV ejection fraction and no visually detectable wall motion abnormality before surgery.(ABSTRACT TRUNCATED AT 250 WORDS)     

Significance of preinfarction angina for preservation of left ventricular function in acute myocardial infarction.

The effect of preinfarction angina on the preservation of left ventricular function was evaluated with the use of cineventriculography in 37 patients who had either total or subtotal occlusion of the proximal left anterior descending coronary artery during the convalescent period of myocardial infarction. In 15 patients who had preinfarction angina more than 1 week before the onset of acute myocardial infarction (group A), the global left ventricular ejection fraction was 54 +/- 3% (SEM) and regional wall motion in the infarct area was 10 +/- 3%. In 10 patients who had preinfarction angina occurred within 1 week before the onset of acute myocardial infarction (group B), the left ventricular ejection fraction and regional wall motion in the infarct area were 42 +/- 3% and 1 +/- 2%, respectively. In 12 patients without preinfarction angina (group C), the left ventricular ejection fraction and regional wall motion in the infarct area were 38 +/- 3% and -1 +/- 2%, respectively. In groups B and C, both the left ventricular ejection fraction and regional wall motion in the infarct area were lower than those in group A (p less than 0.05). The collateral circulation at the onset of acute myocardial infarction was better in group A compared with groups B and C (p less than 0.05). Thus the collateral circulation, promoted by repetitive anginal episodes indicative of myocardial ischemia, causes the preservation of myocardial function.     

Echocardiographic evaluation of left ventricular function during coronary artery angioplasty

Balloon occlusion of a stenotic coronary artery during percutaneous coronary artery angioplasty provides a unique opportunity to study the effect of acute myocardial ischemia on left ventricular (LV) function. Simultaneous M-mode and 2-dimensional (2-D) echocardiograms and a 6-lead electrocardiogram were recorded during 20 episodes of coronary artery occlusion and release in 12 patients. No patient had previous myocardial infarction and all had normal LV function by angiography. All patients had isolated single coronary artery disease, with left anterior descending stenosis in 8 and right coronary stenosis in 4. In 18 of 20 episodes (90%), M-mode echocardiography during balloon occlusion revealed a significant (p less than 0.001) decrease in LV systolic, diastolic and percent systolic wall thickness; systolic excursion; systolic and diastolic endocardial velocities; and fractional shortening. These changes were observed in the area of the ventricular septum in patients with left anterior descending occlusion and posteroinferior wall in those with right coronary artery occlusion. Two-dimensional echocardiography revealed varying degrees of hypokinesia, akinesia and dyskinesia during balloon occlusion in 18 instances. The echocardiographic changes were observed within 15 to 20 seconds of balloon occlusion and resolved 10 to 20 seconds after balloon deflation. All patients who had echocardiographic changes during balloon occlusion also had concomitant electrocardiographic (ECG) ST-segment elevation, whereas 2 patients with normal LV function had no ECG changes. Both of these patients had profuse collateral blood supply to the stenotic coronary artery. The echocardiographic and ECG abnormalities increased proportionately to the length of balloon occlusion. This study confirms previous animal and recent human studies of transient LV dysfunction during coronary occlusion.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hemodynamic and echocardiographic assessment of the effects of diltiazem during transient occlusion of the left anterior descending coronary artery during percutaneous transluminal coronary angioplasty

The effects of diltiazem during transient myocardial ischemia were studied in 17 patients (age 58 +/- 11 years, 12 men, 5 women) undergoing 1-vessel left anterior descending percutaneous transluminal coronary angioplasty (PTCA). After hemodynamic, echocardiographic and electrocardiographic data were obtained during the control ischemic periods, diltiazem (10 mg intravenous bolus with 500 micrograms/min infusion) was given and 15 minutes later ischemia reinduced. Diltiazem reduced mean arterial pressure (113 +/- 16 to 95 +/- 15 mm Hg, p less than 0.05) and heart rate-pressure product (p less than 0.05) with no change in heart rate, pulmonary pressures or coronary (sinus, thermodilution technique) blood flow at rest. After diltiazem, times to ischemia-induced 1.0 mm ST-segment elevation (28 +/- 10 to 42 +/- 17 seconds, p less than 0.05) and new left ventricular wall motion abnormalities (by 2-dimensional echocardiography, 24 +/- 8 to 36 +/- 12 seconds, p less than 0.001) were prolonged without significant augmentation of great cardiac vein flow during coronary occlusion. Left ventricular (LV) ejection fraction decreased from 51 +/- 7 to 41 +/- 12% (p less than 0.05) during control ischemia, but declined less after diltiazem (54 +/- 12 to 47 +/- 14%, difference not significant; 47 +/- 14 vs 41 +/- 12%, p less than 0.01). Diltiazem can attenuate, but not abolish, some of the effects of myocardial ischemia on LV function during transient coronary artery occlusion. These data support the use of diltiazem as a beneficial adjunct that may be used acutely and safely during routine PTCA.     

Comparison of mental stress-induced myocardial ischemia in coronary artery disease patients with versus without left ventricular dysfunction

To examine the susceptibility to myocardial ischemia with mental stress in patients who have coronary artery disease and normal left ventricular (LV) function versus those who have impaired LV function, we examined 58 patients who had coronary artery disease, including 22 who had normal LV function (ejection fraction >/=50%), 16 who had mild to moderate LV dysfunction (ejection fraction 30% to 50%), and 20 who had severe LV dysfunction (ejection fraction 3. At comparable double products across the 3 groups, ischemia was induced with mental stress more frequently in patients who had severe LV dysfunction (50%) than in those who had normal LV function (9%; p <0.01). The frequency of exercise-induced ischemia was different only between those who had mild/moderate LV dysfunction and those who had normal LV function (56% vs 18%, respectively, p <0.05). The pattern of mental stress versus exercise ischemia differed between groups (p <0.02): there was a higher prevalence of mental stress ischemia versus exercise ischemia in patients who had severe LV dysfunction (p = 0.06), a marginally higher prevalence of exercise versus mental stress ischemia in those who had moderate LV dysfunction (p = 0.07), and no difference in mental stress versus exercise ischemia in those who had normal LV function. Thus, at comparable double products during mental stress and similar extent of coronary artery disease, ischemia with mental stress was induced more frequently in patients who had severe LV dysfunction than in those who had normal LV function. These data suggest that mental stress ischemia may be of particular clinical importance in patients who have coronary artery disease and LV dysfunction.     

Improved left ventricular diastolic filling in patients with coronary artery disease after percutaneous transluminal coronary angioplasty

Left ventricular (LV) diastolic filling is abnormal at rest in many patients with coronary artery disease (CAD), even in the presence of normal resting LV systolic function. To determine the effects of improved myocardial perfusion on impaired. LV diastolic filling, we studied 25 patients with one-vessel CAD by high-temporal-resolution radionuclide angiography before and after percutaneous transluminal coronary angioplasty (PTCA). No patient had ECG evidence of previous myocardial infarction. Despite normal regional and global LV systolic function at rest in all patents, LV diastolic filling was abnormal (peak LV filling rate [PFR] less than 2.5 end-diastolic volumes (EDV)/sec or time to PFR greater than 180 msec) in 17 of 25 patients. Twenty-three patients had abnormal LV systolic function during exercise. After successful PTCA, LV ejection fraction and heart rate at rest were unchanged, but LV ejection fraction during exercise increased, from 52 +/- 8% (+/- SD) to 63 +/- 5% (p less than 0.001). LV diastolic filling at rest improved: PFR increased from 2.3 +/- 0.6 to 2.8 +/- 0.5 EDV/sec (p less than 0.001) and time to PFR decreased from 181 +/- 22 to 160 +/- 18 msec (p less than 0.001). Thus, a reduction in exercise-induced LV systolic dysfunction after PTCA, reflecting a reduction in reversible ischemia, was associated with improved LV diastolic filling at rest. These data suggest that in many CAD patients with normal resting LV systolic function and without previous infarction, abnormalities of resting LV diastolic filling are not fixed, but appear to be reversible manifestations of impaired coronary flow.     

Effects of pacing-induced and balloon coronary occlusion ischemia on left atrial function in patients with coronary artery disease

OBJECTIVES: The aim of this study was to compare left atrial (LA) function in 16 patients with distal left anterior descending (LAD) and in 16 patients with proximal left circumflex (LCx) coronary artery stenosis at rest and immediately after pacing-induced tachycardia (LAD-pacing [P] and LCx-P) or coronary occlusion (LAD-CO and LCx-CO). BACKGROUND: During left ventricular (LV) ischemia, compensatory augmentation of LA contraction enhances LV filling and performance. The left atrium is supplied predominantly by branches arising from the LCx. Therefore, we hypothesized that one mechanism for the loss of atrial contraction may be ischemic LA dysfunction. METHODS: Left ventricular and LA pressure-area relations were derived from simultaneous double-tip micromanometer pressure recordings and automatic boundary detection echocardiograms. RESULTS: Immediately after pacing or after coronary occlusion, LV end-diastolic pressure, LV relaxation, LA mean pressure and LV stiffness significantly increased in all patients. However, the area of the A loop of the LA pressure-area relation, representing the LA pump function, significantly decreased in groups LCx-P and LCx-CO (from 14+/-3 to 9+/-2, and from 16+/-4 to 9+/-2 mm Hg.cm2, respectively, p < 0.05), whereas it increased in groups LAD-P and LAD-CO (from 12+/-3 to 54+/-10, and from 16+/-3 to 49+/-8 mm Hg.cm2, respectively, p < 0.001). CONCLUSIONS: In patients with LAD stenosis, LV supply or demand ischemia is associated with enhanced LA pump function. However, in patients with proximal LCx stenosis who develop the same type and degree of ischemia, LA branches might have been affected, rendering the LA ischemic and unable to increase its booster pump function.     

Hyperoxemic perfusion of the left anterior descending coronary artery after primary angioplasty in anterior ST-elevation myocardial infarction.

OBJECTIVES: To assess left ventricle function recovery, ST-segment changes, and enzyme kinetic in ST-elevation myocardial infarction patients treated with intracoronary hyperoxemic perfusion (IHP) after primary percutaneous coronary intervention and compare them with the results obtained in control patients. BACKGROUND: IHP has been shown to attenuate microvascular reperfusion injury, which may result in poor LV function recovery despite successful primary percutaneous coronary intervention. METHODS: Twenty seven anterior ST-elevation myocardial infarction patients treated < or = 12 hr after symptom onset by primary percutaneous coronary intervention were subjected to selective IHP into the left anterior descending coronary artery for 90 min. They were compared with 24 anterior ST-elevation myocardial infarction control patients matched in clinical and angiographic characteristics and treated with conventional primary percutaneous coronary intervention. Left ventricular function recovery was evaluated by serial 2D contrast echocardiography. RESULTS: Left anterior descending coronary artery recanalization was successful in all patients. After IHP (100% successful, duration 90 +/- 5.4 min), patients showed a 4.8 +/- 2.2 hr shorter time-to-peak creatine kinase release (P = 0.001), a shorter creatine kinase half-life period (23.4 +/- 8.9 hr vs. 30.5 +/- 5.8 hr, P = 0.006), and a higher rate of complete ST-segment resolution (78% vs. 42%, P = 0.01). A significant improvement of mean left ventricular ejection fraction (from (44 +/- 9)% to (55 +/- 11)%, P < 0.001) and wall motion score index (from 1.77 +/- 0.2 to 1.39 +/- 0.4, P < 0.001) was observed at 3 months in IHP patients only. CONCLUSION: After successful primary coronary intervention, IHP is associated with significant left ventricular function recovery when compared to conventional treatment. Enzyme kinetic and ST-segment changes suggest faster and more complete microvascular reperfusion and may explain the salutary effects of this new therapy on left ventricular function.     

Usefulness of impairment of coronary microcirculation in predicting left ventricular dilation after acute myocardial infarction

The goals of this study were to assess the serial change in coronary blood flow velocity (CBFV) patterns with transthoracic Doppler echocardiography and to decide optimal timing to predict left ventricular (LV) remodeling in patients with anterior acute myocardial infarction. We recorded CBFV of the left anterior descending (LAD) coronary artery with transthoracic Doppler echocardiography and measured diastolic deceleration time (DDT, measured in milliseconds) on days 2, 7, and 21 in 52 patients with anterior acute myocardial infarction treated with primary coronary angioplasty. On day 2, DDT was >/=600 ms in 21 patients (group A) and <600 ms in the other 31 patients (group B). In group B, DDT increased to >/=600 ms in 12 patients on day 7 (group B1), and DDT was still <600 ms in the other 19 patients (group B2). However, DDT became comparable among 3 groups on day 21. Group B2 patients had significant chronic LV dilation (LV end-diastolic volume index in groups A, B1, and B2 at 6 months: 74 +/- 16 vs 81 +/- 17 vs 100 +/- 22. ml/m(2), respectively; p <0.05 vs other groups). Multivariate analysis revealed that DDT <600 ms on day 7 was the only independent variable related to LV remodeling. In conclusion, the CBFV pattern changed toward normalization with time in patients with acute myocardial infarction. Time taken for normalization varied among patients. Persistence of microvascular dysfunction up to 7 days after reperfusion predicted LV remodeling.     

Impact of late coronary artery reperfusion on left ventricular function one month after acute myocardial infarction (results from the ISAM study)

To evaluate the impact of late reperfusion of an infarct-related coronary artery on left ventricular (LV) function in the month after myocardial infarction, findings from 368 patients in the Intravenous Streptokinase in Myocardial Infarction study are presented. All patients had a late peaking in the creatine kinase-MB serum time-activity curve, suggesting absence of early reperfusion. Contrast angiography was performed 1 month after the acute event. The infarct-related coronary artery was patent in 74 of 116 (64%) streptokinase-treated patients and 141 of 252 (56%) patients treated with anticoagulant therapy (placebo group). In all baseline variables, including the actually developed enzymatic and electrocardiographic infarct sizes, there were no differences between the patent- or occluded-artery groups. A patent infarct artery 1 month after infarction was associated with significantly better LV function regardless of the vessel involved and whether or not patients had been treated with streptokinase. Ejection fraction in patients with patent versus occluded artery was 56 +/- 13 versus 50 +/- 14 (p less than 0.0005). Most benefit was noted in patients in whom the proximal left anterior descending coronary artery was affected: ejection fraction was 52 +/- 14 versus 36 +/- 12% (p less than 0.0005). Our data confirm that restoration of adequate flow through an infarct-related coronary artery beyond the time window for actual salvage of ischemic myocardium has a definite beneficial effect on LV function.     

Prognostic implications of myocardial contractile reserve in patients with coronary artery disease and left ventricular dysfunction.

OBJECTIVES: This study was performed to assess the prognostic implications of myocardial contractile reserve (MCR) in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction. BACKGROUND: MCR during dobutamine stress echocardiography (DSE) identifies viable myocardium that may improve in function after revascularization. Whether revascularization influences prognosis of patients with MCR has not been determined. METHODS: We performed DSE in 80 patients with CAD and LV dysfunction (ejection fraction < or =40%). Viable myocardium was defined in dysfunctional myocardial segments as enhanced thickening and contraction during low-dose dobutamine (5 to 10 mcg/kg/min). Serial prospective follow-up was obtained in all patients (mean follow-up 2.2 +/- 1.1 years). RESULTS: Among 52 patients treated medically, there were 20 cardiac deaths. By multivariate analysis, the number of dysfunctional segments demonstrating MCR was the strongest predictor of survival (p < 0.03). Patients with MCR had better initial survival during medical therapy than did those without MCR, but this survival advantage was not maintained beyond three years. In contrast, survival was excellent in patients with MCR who underwent myocardial revascularization. Among 58 patients with MCR in > or =5 myocardial segments, survival at three years was 93 +/- 6% in the 24 patients who were revascularized but only 49 +/- 15% in the 34 treated medically (p < 0.02). CONCLUSIONS: Myocardial contractile reserve is a significant predictor of survival in patients with CAD and LV dysfunction undergoing medical therapy. Although patients with MCR have an initial survival advantage, this advantage is lost over the course of three years. In contrast, survival in patients with significant MCR is enhanced by revascularization.     

Percutaneous transluminal coronary angioplasty in patients with reduced left ventricular ejection fraction: effects on myocardial perfusion and left ventricular response to exercise

Many patients with coronary artery disease treated by percutaneous transluminal coronary angioplasty (PTCA) have a history of previous myocardial injury resulting in a reduced left ventricular ejection fraction (EF). The effects of successful PTCA on myocardial perfusion and left ventricular function in these patients were compared to treatment in patients with normal left ventricular EF. There were 21 patients with a normal EF (mean EF 59 +/- 2%) (Group I) and 15 patients with reduced EF (mean EF 43 +/- 1%) (Group II). Before PTCA a similar degree of reversible myocardial ischemia was present on thallium scintigraphy. At peak exercise left ventricular EF in the Group I patients decreased by 4 +/- 1% compared to 8 +/- 1% in Group II. At one month following successful PTCA there was resolution of reversible myocardial ischemia in both groups. No changes in EF at rest were observed. At the same level of exercise as before PTCA the mean EF was 5 +/- 1% higher than the pretreatment value in Group I and 10 +/- 1% higher in Group II. Thus in this study reversible myocardial ischemia was associated with severe compromise in the left ventricular response to exercise which was substantially improved by PTCA.     

Differential effects on right ventricular function of transient right, left anterior descending and left circumflex coronary occlusions during percutaneous transluminal coronary angioplasty

Right ventricular function was studied by means of a thermodilution catheter before, during and after percutaneous transluminal angioplasty of the proximal right (group 1, n = 8), left anterior descending (group 2, n = 8) or left circumflex (group 3, n = 8) coronary artery. All patients had evidence of myocardial ischemia, with single-vessel disease affecting the proximal segment of one of the three major coronary arteries; no patient had had a previous myocardial infarction and all had normal cardiac function at baseline study. Cardiac index decreased during balloon inflation. Mean pulmonary artery pressure was unaffected in group 1 but increased in group 2 (from 19 +/- 5 to 31 +/- 11 mm Hg, p less than 0.01) and in group 3 (from 19 +/- 2 to 22 +/- 5 mm Hg, p less than 0.05). Right ventricular ejection fraction decreased from 62 +/- 9% to 52 +/- 10% (p less than 0.01) in group 1 and from 64 +/- 7% to 44 +/- 10% (p less than 0.005) in group 2, and returned to normal within 2 min after balloon deflation in both groups. In group 3, right ventricular ejection fraction was unchanged during balloon inflation (58 +/- 5% at baseline, 58 +/- 9% at 60 s, p = NS). Therefore, brief occlusion of the proximal segments of the left anterior descending or right coronary artery results in marked alteration of right ventricular performance that is probably caused by right ventricular free wall ischemia in the right coronary group and by the concomitant effects of septal ischemia and increased right ventricular afterload in the left anterior descending artery group.(ABSTRACT TRUNCATED AT 250 WORDS)     

Left atrial function in acute transient left ventricular ischemia produced during percutaneous transluminal coronary angioplasty of the left anterior descending coronary artery

Left atrial (LA) function was studied in 32 patients during percutaneous transluminal coronary angioplasty of the proximal left anterior descending artery with a dual micromanometer positioned transseptally in the left atrium and in the left ventricle. In 10 patients LA and left ventricular (LV) cineangiography was performed 30 minutes before percutaneous transluminal coronary angioplasty and 30 seconds after the occlusion of the left anterior descending coronary artery. Thirty seconds after left anterior descending occlusion, LV peak systolic pressure decreased from 135 +/- 12 to 106 +/- 9 mm Hg (p less than 0.05) and LV maximum dP/dt decreased from 1,634 +/- 136 to 1,137 +/- 127 mm Hg/s (p less than 0.01). Simultaneously, LA mean pressure increased from 11 +/- 2 to 29 +/- 1 mm Hg (p 177 +/- 13 to 381 +/- 21 mm Hg (p less than 0.001). There was a difference between LV end-diastolic pressure and LA mean pressure of 1.5 mm Hg at rest and 7.8 mm Hg during ischemia and LA pulse pressure increased from 16 +/- 3 to 26 +/- 3 mm Hg (p less than 0.05) together with increase of LA A and V waves peak pressure. LV stroke volume index decreased from 46 +/- 5 to 43 +/- 3 ml/m2 (difference not significant). The LA maximal volume increased from 18 +/- 2 to 29 +/- 3 ml/m2 (p less than 0.001). LA volume before LA contraction increased from 29 +/- 2 to 54 +/- 3 ml/m2 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Usefulness of granulocyte colony-stimulating factor in patients with a large anterior wall acute myocardial infarction to prevent left ventricular remodeling (the rigenera study)

Intracoronary injection of bone marrow stem cells seems to improve left ventricular (LV) function after acute myocardial infarction (AMI). Granulocyte colony-stimulating factor (G-CSF) could improve myocardial function and perfusion noninvasively through mobilization of stem cells into peripheral blood, although previous clinical trials have produced controversial results. Forty-one patients with large anterior wall AMI at high risk of unfavorable remodeling were randomized 1:2 to G-CSF (10 microg/kg/day for 5 days) or to conventional therapy. All patients underwent successful primary or rescue percutaneous coronary intervention. LV function was assessed by echocardiography before G-CSF administration, > or =5 days after AMI, and at follow-up. Only patients with a LV ejection fraction <50% at baseline were enrolled in the study. After a median follow-up of 5 months (range 4 to 6) patients treated with G-CSF exhibited improvement in LV ejection fraction, from 40 +/- 6% to 45 +/- 6% (p = 0.068) in the absence of LV dilation (LV end-diastolic volume from 147 +/- 33 to 144 +/- 46 ml at follow-up, p = 0.77). In contrast, patients treated conventionally exhibited significant LV dilation (LV end-diastolic volume from 141 +/- 35 to 168 +/- 41 ml, p = 0.002) in the absence of change in LV ejection fraction (from 38 +/- 6% to 38 +/- 8%, p = 0.95). However, when comparing patients treated with G-CSF with controls, variations in these parameters were significantly different at 2-way analysis of variance (p = 0.04 for LV end-diastolic volume, p = 0.02 for LV ejection fraction). In conclusion, G-CSF prevents unfavorable LV remodeling and improves LV function in patients with large anterior wall AMI and decreased LV ejection fraction after successful percutaneous coronary intervention.     

Total occlusion of the left main coronary artery. A clinical, hemodynamic and angiographic profile

Although left main coronary artery stenosis has been extensively revicwed, total occlusion of the left main coronary artery has received scant attention. Six patients were diagnosed at cardiac catheterization as having total occlusion of the left main coronary artery over a period of seven years at two institutions. They ranged in age from 32 to 72 years, and all had symptoms ranging from NYHA Class 1-IV at initial presentation. One patient died three days after coronary artery bypass graft surgery. Of the remaining five, two treated medically are alive four and 40 months after catheterization, and three treated with coronary artery bypass graft surgery are alive three, 66 and 68 months after catheterization. Electrocardiogram showed prior myocardial infarction in three patients, stress tests were positive in three of four patients, and hyperlipidemia was present in the five tested. In the three patients without prior myocardial infarction, left ventricular function was preserved (ejection fractions = 0.52, 0.55 and 0.64; left ventricular end-diastolic pressures = 6, 9 and 14 mm Hg). Injection of the right coronary artery in this group revealed extensive collaterals filling the left coronary artery. The three patients with prior myocardial infarction had impaired left ventricular function (ejection fractions = 0.18, 0.30 and 0.33; left ventricular end diastolic pressures = 26, 35 and 35 mm Hg) and sparse intercoronary collaterals. Patients with total occlusion of the left main coronary artery have a varying clinical presentation and may have prolonged survival. In patients with good collaterals, left ventricular function may be preserved.     

Short- and long-term recovery of left ventricular function predicted at the time of primary percutaneous coronary intervention in anterior myocardial infarction

OBJECTIVES: The aim of this study was to determine predictors of left ventricular (LV) function recovery at the time of primary percutaneous coronary intervention (PCI). BACKGROUND: Angiographic, intracoronary Doppler flow, and electrocardiographic variables have been reported to be predictors of recovery of LV function after acute myocardial infarction (MI). We directly compared the predictive value of Thrombolysis In Myocardial Infarction (TIMI) flow grade, corrected TIMI frame count (cTfc), myocardial blush grade, coronary Doppler flow velocity analysis, and resolution of ST-segment elevation for recovery of LV function in patients undergoing primary PCI for acute MI. METHODS: We prospectively studied 73 patients who underwent PCI for an acute anterior MI. Recovery of global and regional LV function was measured using an echocardiographic 16-segment wall motion index (WMI) before PCI, at 24 h, at one week, and at six months. Directly after successful PCI, coronary flow velocity reserve (CFR), cTfc, TIMI flow grade, and myocardial blush grade were assessed. RESULTS: Mean global and regional WMI improved gradually over time from 1.86 +/- 0.23 before PCI to 1.54 +/- 0.34 at six-month follow-up (p < 0.0001) and from 2.39 +/- 0.30 before PCI to 1.87 +/- 0.48 at six-month follow-up (p < 0.0001), respectively. Multivariate analysis revealed CFR as the only independent predictor for global and regional recovery of LV function at six months. CONCLUSIONS: Doppler-derived CFR is a better prognostic marker for LV function recovery after anterior MI than other currently used parameters of myocardial reperfusion.     

Differences in coronary flow and myocardial metabolism at rest and during pacing between patients with obstructive and patients with nonobstructive hypertrophic cardiomyopathy

Fifty patients with hypertrophic cardiomyopathy underwent invasive study of coronary and myocardial hemodynamics in the basal state and during the stress of pacing. The 23 patients with basal obstruction (average left ventricular outflow gradient, 77 +/- 33 mm Hg; left ventricular systolic pressure, 196 +/- 33 mm Hg, mean +/- 1 SD) had significantly lower coronary resistance (0.85 +/- 0.18 versus 1.32 +/- 0.44 mm Hg X min/ml, p less than 0.001) and higher basal coronary flow (106 +/- 20 versus 80 +/- 25 ml/min, p less than 0.001) in the anterior left ventricle, associated with higher regional myocardial oxygen consumption (12.4 +/- 3.6 versus 8.9 +/- 3.3 ml oxygen/min, p less than 0.001) compared with the 27 patients without obstruction (mean left ventricular systolic pressure 134 +/- 18 mm Hg, p less than 0.001). Myocardial oxygen consumption and coronary blood flow were also significantly higher at paced heart rates of 100 and 130 beats/min (the anginal threshold for 41 of the 50 patients) in patients with obstruction compared with those without. In patients with obstruction, transmural coronary flow reserve was exhausted at a heart rate of 130 beats/min; higher heart rates resulted in more severe metabolic evidence of ischemia with all patients experiencing chest pain, associated with an actual increase in coronary resistance. Patients without obstruction also demonstrated evidence of ischemia at heart rates of 130 and 150 beats/min, with 25 of 27 patients experiencing chest pain. In this group, myocardial ischemia occurred at significantly lower coronary flow, higher coronary resistance and lower myocardial oxygen consumption, suggesting more severely impaired flow delivery in this group compared with those with obstruction. Abnormalities in myocardial oxygen extraction and marked elevation in filling pressures during stress were noted in both groups. Thus, obstruction to left ventricular outflow is associated with high left ventricular systolic pressure and oxygen consumption and therefore has important pathogenetic importance to the precipitation of ischemia in patients with hypertrophic cardiomyopathy. Patients without obstruction may have greater impairment in coronary flow delivery during stress.     

Usefulness of myocardial blush grade early and late after primary coronary angioplasty for acute myocardial infarction in predicting left ventricular function

This study sought to analyze the evolution of myocardial perfusion during follow-up after primary angioplasty for acute myocardial infarction (AMI) and relate it to final left ventricular (LV) function. In 101 patients with a first AMI, angiographic myocardial blush grade (MBG) was analyzed immediately after intervention and at follow-up 7.5 +/- 5.6 months later. Cine ventriculography was performed at follow-up angiography to define LV function. Five patients had occluded stents or flow-limiting restenosis. In the remaining patients, myocardial perfusion at follow-up, as defined by MBG, was persistently abnormal in 19 patients (20%), had become normalized from previously abnormal MBG in 30 patients (31%), remained normal in 40 patients (42%), and deteriorated from normal to abnormal in 7 patients (7%). Patients with improvement of abnormal blush determined immediately after intervention to normal blush at follow-up (n = 30) compared with patients with persistently abnormal blush (n = 19) had a better LV ejection fraction at follow-up (53.7 +/- 11.1 vs. 37.4 +/- 9.7%, p <0.001). Evolution of MBG had a better predictive value for LV ejection fraction at follow-up than acute MBG only. Multivariate analysis proved evolution of MBG from AMI to follow-up to be an independent predictor of LV function (R(2) = 0.177, p <0.001) in addition to the initial size of jeopardized myocardium as defined by the sum of ST-segment elevation (R(2) = 0.138, p = 0.001) and infarct location (R(2) = 0.044, p = 0.033). In conclusion, tissue reperfusion after angioplasty for AMI is characterized by frequent improvement over time, as indicated by repeated MBG analysis. Patients with recovery of perfusion have better, final LV function.