Abciximab improves 6-month clinical outcome after rescue coronary angioplasty

Background Few data are available concerning the effects on clinical outcome and left ventricular function of abciximab administration in patients undergoing rescue percutaneous transluminal coronary angioplasty (PTCA) after failed thrombolysis for acute myocardial infarction. The aim of the study was to investigate such effects. Methods Eighty-nine consecutive patients referred to our laboratory from other hospitals for rescue PTCA within 24 hours from the onset of chest pain were prospectively randomized before the procedure to abciximab treatment (44 patients) or placebo (45 patients). No significant differences in baseline characteristics were observed between the 2 groups. Study end points were the occurrence of major adverse cardiac events (MACE) such as death, reinfarction, congestive heart failure, target lesion revascularization, or recurrent ischemia at 30-day and 6-month follow-up and the occurrence of periprocedural bleeding. Results Mean time from symptom onset to reperfusion was 8.5 ± 5.4 hours; rescue PTCA was successful in 96% of patients. The incidence of major, moderate, and minor bleeding was similar in the 2 groups. At 30-day follow-up, the echocardiographic left ventricular wall motion score index showed a significantly higher improvement in the abciximab group versus the placebo group (P < .001). At 6-month follow-up, the incidence of MACE was 11% in the abciximab group versus 38% in the placebo group (P = .004). Abciximab administration (P = .003) and cardiogenic shock (P = .005) were the only independent predictors of the occurrence of MACE at multivariable analysis. Conclusion Treatment with abciximab during rescue PTCA positively affects clinical outcome at 6-month follow-up without increasing periprocedural bleeding. (Am Heart J 2002;143:334-41.)     

Effects of hospital volume on long-term outcomes after percutaneous transluminal coronary angioplasty after acute myocardial infarction

Background Volume of procedures has been associated with short-term outcome after percutaneous transluminal coronary angioplasty. However, the effect of hospital procedural volume on long-term outcome after PTCA is unknown. Methods and Results We analyzed the physician claims and discharge data of 6635 patients who underwent PTCA after acute myocardial infarction (AMI) between 1991 and 1995 in the province of Quebec, Canada. For each administrative year, hospitals in which PTCA was performed were classified into 3 groups: low-volume, <200 procedures per year; medium-volume, 200 to 399 procedures per year; and high-volume, ≥400 procedures per year. Compared with patients in medium-volume and high-volume hospitals, patients in low-volume hospitals were older, had more recent AMI, and were less likely to have been transferred for PTCA. After adjustment for baseline differences, patients in the low-volume and medium-volume groups were more likely to undergo CABG within 6 months compared with patients in the high-volume group (odds ratio [OR] 2.1, 95% CI 1.3-3.3, and OR 1.5, 95% CI 1.2-1.9, respectively). In contrast, patients in the low-volume and medium-volume groups were less likely than patients in the high-volume group to undergo repeat PTCA within 6 months (OR 0.37, 95% CI 0.24-0.58, and OR 0.8, 95% CI 0.70-0.92, respectively). At 6 months, adjusted rates of repeat revascularization, recurrent AMI, or death did not differ between the 3 groups. Conclusion Overall adverse event rates at 6 months after PTCA do not differ between hospital volume groups. The higher rate of CABG in low-volume hospitals and the higher rate of repeat PTCA in high-volume hospitals may represent different physician preferences for the treatment of failed PTCA rather than higher complication rates. (Am Heart J 2002;144:144-50.)     

Long-term outcome and the use of revascularization in patients with heart failure,suspected ischemic heart disease,and large reversible myocardial perfusion defects

Background The potential role of coronary revascularization in the management of patients with congestive heart failure and suspected ischemic heart disease remains to be defined. Myocardial perfusion imaging can identify patients with ischemic heart disease as the etiology for left ventricular dysfunction who might benefit from revascularization. Methods We retrospectively identified heart failure patients with suspected ischemic heart disease who had large reversible perfusion defects to determine their long-term outcome and rate of revascularization. The study group consisted of 77 patients with congestive heart failure, left ventricular ejection fraction <45%, and suspected ischemic heart disease who underwent myocardial perfusion imaging during the period of January 1, 1991, to December 31, 1997, and had large reversible perfusion defects. Results The 5-year mortality rate was 57.6%. The revascularization rate was only 13% for 5 years of follow-up. The number of patients undergoing revascularization was too small to assess its impact on outcome. Conclusion These results indicate a high 5-year mortality rate and a low utilization of coronary revascularization in patients with heart failure and large reversible perfusion defects. The low rate of revascularization reflects at least in part the absence of the generalizability of the existing literature to the optimal means of treating patients with heart failure and myocardial ischemia and points to the need for a randomized clinical trial. (Am Heart J 2002;143:904-9.)     

Reperfusion of Infarct Related Artery Achieved by Direct Percutaneous Transluminal Coronary Angioplasty Counteracts Left Ventricular Remodeling after Acute Myocardial Infarction More Than Thrombolysis

The purpose of this study was to compare the effect of direct percutaneous transluminal coronary angioplasty (PTCA) and intravenous recombinant tissue plasminogen activator (rt-PA) on left ventricular remodeling in patients with acute myocardial infarction (AMI). To address this issue, patients with AMI randomly assigned to direct PTCA or intravenous rt-PA as part of a large multicenter study (Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries [GUSTO] IIb Angioplasty Substudy) were evaluated with two-dimensional echocardiography at predischarge. An echocardiographic infarct size index and the end-diastolic and end-systolic left ventricular volumes were computed. Patients with an infarct size index equal to or higher than the mean value were considered to have a large infarction. Of 26 enrolled patients, 13 were assigned to PTCA (9 successfully reperfused: i.e., TIMI-3 flow after PTCA) and 13 to rt-PA (10 successfully reperfused: i.e., ST resolution after rt-PA). In patients considered successfully reperfused, end-systolic volumes tended to be lower in PTCA patients than in rt-PA patients (43 ± 17 cc vs 59 ± 21 cc, P = 0.09), although there were no differences in infarct size index (7.3 ± 2.8 vs 7.0 ± 2.8) and ejection fraction (52%± 10% vs 46%± 12%). End-systolic volume depended on infarct size index in the overall patient population (r = 0.60, P = 0.007) and in rt-PA patients (r = 0.80, P =0.005), while no correlation was found in PTCA patients. Considering patients with large AMIs, end-systolic volumes were higher in the four patients treated with rt-PA than in the four patients treated with direct PTCA (P < 0.01). Considering all the 26 enrolled patients, these differences were also present, but they did not reach statistical significance. In conclusion, our results suggest that, in patients with large AMIs, adequate reperfusion obtained by direct PTCA has a more marked effect in counteracting ventricular remodeling than that obtained by systemic rt-PA. This beneficial effect of direct PTCA, independent of any reduction in regional wall-motion abnormalities, should be taken into account when comparing the clinical value of direct PTCA with that of systemic thrornbolysis in the treatment of AMI.     

Influence of treatment delay on long-term left ventricular function in patients with acute myocardial infarction successfully treated with primary angioplasty

BACKGROUND: Myocardial salvage has been shown to be dependent on the time elapsed from the onset of acute myocardial infarction (AMI) to reperfusion. The aim of this study was to evaluate the importance of time to reperfusion for left ventricular function recovery after primary angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) for AMI. METHODS: Ninety-five patients undergoing long-term successful PTCA for AMI were studied. Echocardiography was performed before and 3, 7, 30, 90, and 180 days after PTCA. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI), ejection fraction, and left ventricular wall motion score index (WMSI) were evaluated. RESULTS: Patients were divided into group A, 23 patients reperfused within 2 hours; group B, 32 patients reperfused between 2 and 4 hours; group C, 22 patients reperfused between 4 and 6 hours; and group D, 18 patients reperfused between 6 and 12 hours. Both EDVI and ESVI were reduced in groups A and B at 90 days. Groups C and D did not show any changes of EDVI and ESVI at any stage throughout the study. Ejection fraction improved only in groups A and B at 30, 90, and 180 days. At study entry, WMSI was similar in all groups. After 7 days, in group A and in group B, WMSI was improved, no changes were observed in group C, and a mild deterioration was observed in group D at 3 and 7 days. Subsequent evaluations showed progressive improvement of WMSI in all groups. CONCLUSIONS: Myocardial salvage is achieved only in patients revascularized within 4 hours from AMI onset. However, revascularization after 6 hours may be worthwhile by preventing ventricular remodeling.     

Prognostic importance of systolic and diastolic function after acute myocardial infarction

Background Although risk stratification after acute myocardial infarction (AMI) often is focused on systolic left ventricular (LV) function, it appears that a more complete study of ventricular function including assessment of LV filling would be useful. Doppler echocardiography allows assessment of LV filling, and with the use of the Tei index (sum of isovolumic relaxation and contraction times divided by ejection time), a global estimate of ventricular function may be obtained. Therefore, the aim of this study was to determine the prognostic importance of LV systolic, diastolic, and overall LV function in a large consecutive population with AMI.Methods Echocardiography was performed within 6 days of AMI. LV systolic, diastolic, and global function was assessed by means of wall motion index (WMI), mitral flow pattern, and Tei index. The primary end point was all-cause death.Results Of 799 enrolled patients, 197 died during a median follow-up of 34 months. In a multivariate model including WMI and clinical parameters, WMI had important prognostic information. When mitral filling pattern and quartiles of Tei index were added to the model, restrictive filling (mitral deceleration time <140 ms) was associated with a risk ratio of 1.9 (95% CI 1.3-2.7, P < .0001, Tei index values of >0.68/0.56-0.68/0.46-0.55/<0.46 were associated with risks of 4.0 [2.1-6.9]/2.3 [1.5-3.9]/2.1 [1.2-3.6]/1.0, P < .001). In this model, WMI had no prognostic value (P = .18).Conclusions Mitral deceleration time and the Tei index have independent and important prognostic value after AMI. (Am Heart J 2003;145:147-153.)     

Effects of bisoprolol fumarate on left ventricular size, function, and exercise capacity in patients with heart failure: analysis with magnetic resonance myocardial tagging

Background Recent data suggest that beta-blockers can be beneficial in subgroups of patients with chronic heart failure (CHF). For metoprolol and carvedilol, an increase in ejection fraction has been shown and favorable effects on the myocardial remodeling process have been reported in some studies. We examined the effects of bisoprolol fumarate on exercise capacity and left ventricular volume with magnetic resonance imaging (MRI) and applied a novel high-resolution MRI tagging technique to determine myocardial rotation and relaxation velocity. Methods Twenty-eight patients (mean age, 57 ± 11 years; mean ejection fraction, 26 ± 6%) were randomized to bisoprolol fumarate (n = 13) or to placebo therapy (n = 15). The dosage of the drugs was titrated to match that of the the Cardiac Insufficiency Bisoprolol Study protocol. Hemodynamic and gas exchange responses to exercise, MRI measurements of left ventricular end-systolic and end-diastolic volumes and ejection fraction, and left ventricular rotation and relaxation velocities were measured before the administration of the drug and 6 and 12 months later. Results After 1 year, heart rate was reduced in the bisoprolol fumarate group both at rest (81 ± 12 before therapy versus 61 ± 11 after therapy; P < .01) and peak exercise (144 ± 20 before therapy versus 127 ± 17 after therapy; P < .01), which indicated a reduction in sympathetic drive. No differences were observed in heart rate responses in the placebo group. No differences were observed within or between groups in peak oxygen uptake, although work rate achieved was higher (117.9 ± 36 watts versus 146.1 ± 33 watts; P < .05) and exercise time tended to be higher (9.1 ± 1.7 minutes versus 11.4 ± 2.8 minutes; P = .06) in the bisoprolol fumarate group. A trend for a reduction in left ventricular end-diastolic volume (−54 mL) and left ventricular end-systolic volume (−62 mL) in the bisoprolol fumarate group occurred after 1 year. Ejection fraction was higher in the bisoprolol fumarate group (25.0 ± 7 versus 36.2 ± 9%; P < .05), and the placebo group remained unchanged. Most changes in volume and ejection fraction occurred during the latter 6 months of treatment. With myocardial tagging, insignificant reductions in left ventricular rotation velocity were observed in both groups, whereas relaxation velocity was reduced only after bisoprolol fumarate therapy (by 39%; P < .05). Conclusion One year of bisoprolol fumarate therapy resulted in an improvement in exercise capacity, showed trends for reductions in end-diastolic and end-systolic volumes, increased ejection fraction, and significantly reduced relaxation velocity. Although these results generally confirm the beneficial effects of beta-blockade in patients with chronic heart failure, they show differential effects on systolic and diastolic function. (Am Heart J 2002;143:676-83.)     

Tako-tsubo-like left ventricular dysfunction with ST-segment elevation: a novel cardiac syndrome mimicking acute myocardial infarction

Background Peculiar asynergy, which consists of hypokinesis or akinesis from the mid portion to the apical area and hyperkinesis of the basal area on contrast left ventriculogram, is rare. Because the end-systolic left ventriculogram looks like a “tako-tsubo,” which was used for trapping octopuses in Japan, we proposed the term “tako-tsubo-like left ventricular dysfunction.” Our aim was to evaluate its clinical features and causes. Methods We studied 30 patients with tako-tsubo-like left ventricular dysfunction without significant coronary artery disease. We assessed its pathophysiologic mechanisms by coronary spasm provocation test, endomyocardial biopsy, measurement of virus titer, and measurement of circulating catecholamine levels. Results Patient age ranged from 55 to 83 years. Twenty-eight were women and 2 were men. Tako-tsubo-like left ventricular dysfunction was dramatically resolved on predischarge left ventriculogram at 11.3 ± 4.3 days. Acute coronary angiography revealed spontaneous multivessel coronary spasm in 3 patients. Among 14 patients, ergonovine or acetylcholine induced epicardial single coronary spasm in 4 patients and multivessel coronary spasm in 6 patients. Spontaneous microvascular spasm occurred at predischarge in 1 patient. An endomyocardial biopsy specimen in 3 patients and measurement of virus titer in 7 patients did not show evidence of acute myocarditis. Circulating norepinephrine was normal or slightly elevated in 6 patients. Conclusions We showed clinical features of a novel cardiac syndrome with tako-tsubo-like left ventricular dysfunction. Although the precise cause remains unclear, simultaneous multivessel coronary spasm at the epicardial artery or microvascular levels may contribute to the onset of tako-tsubo-like left ventricular dysfunction. (Am Heart J 2002;143:448-55.)     

Importance of time-to-reperfusion in patients with acute myocardial infarction with and without cardiogenic shock treated with primary percutaneous coronary intervention

Background Time-to-treatment is important for survival in patients with acute myocardial infarction (AMI) treated with fibrinolytic therapy, but the importance of time-to-treatment with primary percutaneous coronary intervention (PCI) is controversial. Previous studies evaluating the importance of time-to-treatment with primary PCI have not analyzed patients with cardiogenic shock separately. Methods Consecutive patients with AMI (n = 1843) treated with primary PCI were prospectively enrolled in the LeBauer Cardiovascular Research Foundation Registry. Late clinical follow-up was obtained in 98% of patients, at a mean time of 6.1 years. Results Reperfusion times were longer in women and patients with diabetes mellitus and shorter in patients with prior myocardial infarction. In patients with shock (n = 138), the inhospital mortality rate increased progressively with increasing time-to-reperfusion (<3 hours, 31%; 3-<6 hours, 50%; ≥6 hours, 62%; P = .01), whereas in patients without shock (n = 1705), inhospital and late mortality rates were similar across 3 categories of time to reperfusion (<3 hours, 5.8%; 3-<6 hours, 4.6%; ≥6 hours, 4.8%; P = .46). After adjusting for differences in baseline variables, reperfusion time was a significant independent predictor of inhospital mortality in patients with shock, but not in patients without shock. Conclusions Reperfusion time with primary PCI is important for survival in patients with shock, but appears to be less important in patients without shock. These data emphasize the importance of achieving early reperfusion in patients with shock and have implications on the triage of patients without shock for mechanical reperfusion and the mechanism of benefit of reperfusion therapy with primary PCI. (Am Heart J 2003;145:708-15.)     

Randomized,double-blind,placebo-controlled long-term study of isosorbide-5-mononitrate therapy in patients with left ventricular dysfunction after acute myocardial infarction

Background Nitrates are often administrated with a variety of other pharmacologic agents in the management of chronic heart failure (CHF). However, limited information is available concerning the long-term effects in patients with evidence of left ventricular (LV) dysfunction after acute myocardial infarction (AMI) already treated with standard heart failure therapy.Methods In a randomized, double-blind, placebo-controlled trial, we evaluated the effects of a 60 mg dose of isosorbide-5-mononitrate (IS-5-MN) given daily for 11 months to 47 patients with clinical or echocardiographic evidence of left ventricular dysfunction after acute myocardial infarction. Forty-five patients received a placebo.Results Invasive hemodynamic measurements did not show any difference between the treatment regimens. Overall changes in echocardiographic measurements were not significantly different between IS-5-MN therapy and the placebo groups. However, in a prespecified subgroup with left ventricular ejection fraction ≤40% at baseline, IS-5-MN therapy resulted in a lesser increase of end-diastolic volume index than the placebo (P = .047). IS-5-MN significantly reduced the serum concentration of atrial natriuretic peptide (mean 20.0 pmol/L, 95% CI 7.7-32.3, P = .002), whereas the placebo did not (P = .041 for the difference between the groups). The proportion of patients taking diuretics was significantly reduced in the IS-5-MN group, from 30 of 44 to 20 of 44 (P = .02), but not with placebo, which remained at 27 of 43 (P = 1.0, with P = .048 for the difference between the regimens).Conclusions Oral, long-term IS-5-MN therapy resulted in lower atrial natriuretic peptide levels and reduced the need for additional diuretics. Less LV dilatation was observed in patients with more severe LV dysfunction at baseline. (Am Heart J 2003;145:e1.)     

Immunoglobulin G3 cardiac myosin autoantibodies correlate with left ventricular dysfunction in patients with dilated cardiomyopathy: immunoglobulin G3 and clinical correlates

Background Effector functions of an aberrant immune response have been implicated in the pathogenesis of idiopathic dilated cardiomyopathy (DCM). The immunologic determinants of myocardial dysfunction, however, remain poorly understood. This study sought to determine the relation of different immunologic responses to hemodynamic dysfunction in DCM. Methods Immunoglobulin (Ig) G class/subclass response ELISA (enzyme-linked immunosorbent assay) against cardiac myosin heavy chain, histologic characteristics (DALLAS criteria), immunohistochemistry, plasma interleukin-4 and plasma interferon gamma (IFN-γ) were determined in patients (n = 76) with clinically suspected myocarditis or DCM. Patients were prospectively evaluated, both clinically and hemodynamically, on admission (baseline) and at 6-month follow-up. Results Indices of hemodynamic dysfunction (by cardiac catheterization and transthoracic echocardiography) correlated significantly with an Ig subclass response. IgG3 levels correlated with left ventricular ejection fraction (P = .02), pulmonary capillary wedge pressure (P < .0001), left ventricular end-systolic volume index (P = .002), left ventricular end-diastolic volume index (P = .033), left ventricular end-diastolic pressure (P = .04), right ventricular end-diastolic pressure (P = .039), and left ventricular end-systolic dimension and left ventricular end-diastolic dimension (P < .05). Patients positive for IgG3 (predominantly male, P = .01) had depressed left ventricular ejection fraction (≤45%, relative risk 3.0, 95% CI 1.5-5.7, P = .005) at baseline and 6 months. Mitral-septal separation at follow-up improved in patients negative for IgG3 (P = .018), and the number of patients on conventional therapy in this group declined at 6-month follow-up (P < .05). Lymphocyte counts/high-power field; CD2, CD3, CD4, and CD8 (independent of IgG class/subclass response and left ventricular dysfunction) were significantly higher in patients positive for IFN-γ (25%). A positive IFN-γ response was higher in patients positive for IgG3. These patients, positive for IgG3 and IFN-γ (10%), had significantly shorter duration of clinical symptoms: 0.17 years (0.12-2.36 y) versus 1.01 years (0.49-5.35 y, P = .04). Conclusion IgG3 reactivity correlated with depressed myocardial dysfunction. This may render this subclass Ig a surrogate target for therapeutic intervention in DCM. With IFN-γ, IgG3 may reflect a more aggressive disease. (Am Heart J 2002;143:1076-84.)     

Angiographic no-reflow phenomenon as a predictor of adverse long-term outcome in patients treated with percutaneous transluminal coronary angioplasty for first acute myocardial infarction

OBJECTIVES: We sought to elucidate the long-term prognostic importance of angiographic no-reflow phenomenon after percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI). BACKGROUND: Angiographic no-reflow phenomenon, a reduced coronary antegrade flow (Thrombolysis in Myocardial Infarction [TIMI] flow grade < or =2) without mechanical obstruction after recanalization, predicts poor left ventricular (LV) functional recovery and survival in the early phase of AMI. We hypothesized that angiographic no-reflow phenomenon also predicts long-term clinical outcome. METHODS: We studied 120 consecutive patients with their first AMI treated by PTCA without flow-restricting lesions. The patients were classified as either no-reflow (n = 30) or reflow (TIMI-3) (n = 90) based on post-PTCA cineangiograms to follow up (5.8 +/- 1.2 years) for cardiac death and nonfatal events. RESULTS: Patients with no-reflow had congestive heart failure (p < 0.0001), malignant arrhythmia (p = 0.038), and cardiac death (p = 0.002) more often than did those with reflow. Kaplan-Meier curves showed lower cardiac survival and cardiac event-free survival (p < 0.0001) in patients with no-reflow than in those with reflow. Multivariate analyses disclosed that no-reflow phenomenon was an independent predictor of long-term cardiac death (relative risk [RR] 5.25, 95% confidence interval [CI] 1.85 to 14.9, p = 0.002) and cardiac events (RR 3.71, 95% CI 1.79 to 7.69, p = 0.0004). At follow-up, survivors with no-reflow had higher end-diastolic and end-systolic LV volume indices and plasma brain natriuretic peptide levels, and lower LV ejection fractions (p = 0.0002, p < 0.0001, p = 0.002, p < 0.0001, respectively) than did those with reflow, indicating that no-reflow may be involved in LV remodeling. CONCLUSIONS: Angiographic no-reflow phenomenon strongly predicts long-term cardiac complications after AMI; these complications are possibly associated with LV remodeling.     

Detection of left ventricular enlargement and impaired systolic function with plasma N-terminal pro brain natriuretic peptide concentrations

Background Brain- and N-terminal pro brain natriuretic peptide (NT-proBNP) have been identified as promising markers for heart failure. However, previous studies have revealed that they may hold insufficient diagnostic power for implementation into clinical practice because of a significant overlap in the range of plasma levels between healthy subjects and subjects with heart failure. We hypothesized that imprecision of the reference method (ie, the echocardiographic evaluation of left ventricular [LV] function) may have affected results from those earlier studies. We therefore wanted to investigate the diagnostic potential of NT-proBNP with magnetic resonance imaging as the reference method for the cardiac measurements. Methods Forty-eight patients with stable symptomatic heart failure in New York Heart Association functional classifications II to IV were examined once with blood samples and magnetic resonance imaging along with 20 age-matched and gender-matched healthy control subjects. Results NT-proBNP was associated with LV end-diastolic (r = 0.69; P < .0001) and end-systolic (r = 0.73; P < .0001) volume indices, LV mass index (r = 0.69; P < .0001), and LV ejection fraction (r = −0.75; P < .0001). Receiver operating characteristic curves were calculated for the ability of NT-proBNP to detect LV end-diastolic volume index (>105 mL · m⁻²[cut-off]; sensitivity/specificity, 82%/87%), LV end-systolic volume index (>35 mL · m⁻²; sensitivity/specificity, 86%/86%), LV mass index (>152 g · m⁻²; sensitivity/specificity, 85%/86%), and LV ejection fraction (<58%; sensitivity/specificity, 84%/85%) deviating more than 2 standard deviations from control values. Conclusion NT-proBNP is a powerful marker for LV dimensions and systolic function in patients with heart failure and discriminates well between healthy subjects and subjects with impaired LV systolic function or increased LV dimensions. (Am Heart J 2002;143:923-9.)     

ST-segment re-elevation unrelated to left ventricular ejection fraction or volume after anterior wall acute myocardial infarction treated with successful reperfusion

Ventricular remodeling is a major determinant of the long-term prognosis of patients with acute myocardial infarction (AMI). No previous study examined the relation of ST-segment re-elevation to left ventricular (LV) volume and function in patients with successful reperfusion. We examined the relation of ST-segment re-elevation to LV function and volume indices in 51 patients with anterior wall AMI who underwent successful reperfusion by direct coronary angioplasty. A 12-lead electrocardiogram was recorded once a day until 7 days after the onset of AMI. ST-segment shift was measured and Sigma ST was defined as the sum of ST-segment elevation obtained from leads V2, V3, and V4. ST-segment re-elevation was defined as present when the difference between maximal and minimal Sigma ST (Delta ST) was >0.3mV. LV indices were obtained from left ventriculography performed approximately 1 month after the onset of AMI. ST-segment re-elevation was observed in 15 patients (29%). No significant differences were observed between the ST- re-elevation group and non-ST-re-elevation group in LV ejection fraction (49.4+/-14.0 vs. 51.2+/-11.5%), LV end-systolic volume index (35.8+/-13.1 vs. 33.8+/-12.5 mL/m(2)) or LV end-diastolic volume index (69.7+/-12.8 vs. 68.3+/-14.4 mL/m(2)). The difference between maximal and minimal Sigma ST (Delta ST) was not significantly correlated with any LV index examined. In conclusion, the present study revealed that ST-segment re-elevation after successful reperfusion in anterior wall AMI patients was not related to LV volume or function, indicating that ST-re-elevation is not a clinically meaningful indicator of LV remodeling.     

Effects of exercise training on left ventricular volumes and function in patients with nonischemic cardiomyopathy: application of magnetic resonance myocardial tagging

Background Exercise training is now an accepted component of the therapeutic regimen in patients with heart failure and underlying ischemia, but few data are available on the effects of training in patients with nonischemic dilated cardiomyopathy. Methods Twenty-four patients (mean age 55 ± 9 years, mean ejection fraction 26.6% ± 10%) were randomized to an exercise (n = 12) or a control (n = 12) group. Patients in the exercise group underwent 5 45-minute sessions of supervised training per week. Before and after the 2-month study period, exercise testing with respiratory gas exchange and lactate analysis was performed, left ventricular volumes and ejection fraction were measured with magnetic resonance imaging, and left ventricular rotation and relaxation velocities were measured with a novel magnetic resonance imaging tagging technique. Results Training resulted in increases in peak oxygen uptake (VO₂) (21.7 ± 4 mL/kg/min to 25.3 ± 5 mL/kg/min, P < .05) and VO₂ at the lactate threshold (12.8 ± 4 mL/kg/min to 19.0 ± 5 mL/kg/min, P < .01). No differences were observed within or between groups in left ventricular end-diastolic volume, end-systolic volume, or ejection fraction. Velocity of left ventricular rotation during systole was unchanged in both groups, and relaxation velocity was higher after training in the exercise group (21.2 ± 5 degrees/s versus 29.7 ± 12 degrees/s, P < .05). Conclusion Training resulted in increases in peak VO₂ and VO₂ at the lactate threshold. Left ventricular volumes and systolic function (ie, ejection fraction and rotation velocity) were unchanged with training, suggesting that training in patients with dilated cardiomyopathy does not lead to further myocardial damage. However, the increase in relaxation velocity after exercise training indicates an improvement in diastolic function. The latter finding suggests an additional potential benefit of exercise training in patients with dilated cardiomyopathy. (Am Heart J 2002;144:719-25.)     

Left ventricular remodeling in the first year after acute myocardial infarction and the predictive value of N-terminal pro brain natriuretic peptide

Background Left ventricular (LV) remodeling after myocardial infarction (MI) has received much attention because of its severe impact on morbidity and mortality rates. However, the incidence and extent of LV remodeling in a modern infarct population who were offered antiremodeling treatment in compliance with daily clinical practice is unknown. The purpose of this study was to clarify this issue and to evaluate the predictive value of N-terminal pro brain natriuretic peptide (NT-proBNP). Methods Forty-two patients with a first transmural MI were examined after 1 week, 1 month, 3 months, 6 months, and 1 year with blood samples and magnetic resonance imaging. Results In 12 patients (29%), LV end-diastolic volume index (LVEDVI) and LV end-systolic volume index (LVESVI) increased by 24% and 22% (P <.0001; P = .01). In 12 patients (29%), LVEDVI and LVESVI decreased by 19% and 23% (P <.0001; P = .0005), whereas the remaining 18 patients (43%) had stable conditions regarding these LV measures. LV ejection fraction at baseline was significantly reduced in all patient categories but was unchanged over time. Elevated NT-proBNP level at baseline was identified as an independent predictor of increase in LVEDVI during follow-up examination (P = .007). A baseline level of NT-proBNP >115 pmol/L identified patients who later had LV dilatation develop with a sensitivity and specificity of 89% and 68% (area under curve = 0.77). Conclusion In this 1-year follow-up study of patients with a first transmural MI, approximately 30% had significant increments develop in LVEDVI and LVESVI, and LV ejection fraction remained unchanged. Patients in whom LV dilatation developed could be identified early after the MI with elevated plasma levels of NT-proBNP. (Am Heart J 2002;143:696-702.)     

Two-decade-long trends (1975-1997) in the incidence,hospitalization, and long-term death rates associated with complete heart block complicating acute myocardial infarction: a community-wide perspective

Background The purpose of this community-wide study was to describe a >2-decade-long experience (1975-97) in the incidence and death rates associated with complete heart block (CHB) in patients with acute myocardial infarction (AMI). Limited population-based data exist describing recent, and changes with time therein, incidence and case-fatality rates associated with CHB complicating AMI. Methods We conducted an observational study of 9082 metropolitan Worcester, Mass, residents (1990 census = 437,000) hospitalized with validated AMI in all greater Worcester hospitals during 11 1-year periods between 1975 and 1997. Results Overall, CHB developed in 5.0% of patients with AMI. The incidence rates of CHB declined in the periods studied (6.0% in 1975/78 vs 3.1% in 1997). Declines in the occurrence of CHB were noted in patients with anterior or inferior/posterior MI. These trends remained after adjustment for other factors that might affect the risk of CHB. Patients in whom CHB developed experienced significantly higher hospital death rates than patients in whom CHB did not develop (46.8% vs 14.6%). However, improving trends in the hospital survival rate of patients with CHB were observed between 1975/78 (47.4% surviving) and 1997 (61.3% surviving). Patients in whom CHB developed during hospitalization were not at increased risk for dying after hospital discharge. Conclusions Our findings indicate that the incidence of CHB complicating AMI has declined with time. The hospital prognosis of patients in whom CHB developed has improved, but these patients remain at an increased risk of hospital mortality. The long-term prognosis of patients with inferior MI and CHB is similar to that of patients in whom CHB did not develop. Patients with anterior MI and CHB may be at an increased risk of long-term mortality. (Am Heart J 2003;145:500-7.)     

Reperfusion syndrome: relationship of coronary blood flow reserve to left ventricular function and infarct size

OBJECTIVES: We tested the hypothesis that the reperfusion syndrome (RS), defined as an additional elevation of the ST segment upon reperfusion, may be a marker of microcirculatory reperfusion injury during acute myocardial infarction (AMI). BACKGROUND: The pathophysiology of the RS is unknown, and its prognostic implications are controversial. METHODS: Twenty-one patients with an anterior AMI treated < or =12 h after onset by primary coronary angioplasty (PTCA) were studied. Coronary velocity reserve (CVR), an index of microcirculatory function, was measured using a Doppler guidewire. Left ventricular (LV) ejection fraction, infarct size (percent defect) and LV end-systolic volume index (LVESVi) were evaluated by radionuclide ventriculography, 201T1 single-photon emission computed tomography and contrast ventriculography, respectively. RESULTS: Baseline ST elevation and pain-to-TIMI 3 time were similar in patients with and without RS. Patients with RS (10/21) had a lower post-PTCA CVR than patients without RS (median [95% confidence interval]: 1.2 [1-1.3] vs. 1.6 [1.5-1.7], p < 0.005). Even though predischarge CVR was similar in the two groups, infarct size at six weeks (26 [21 to 37] vs. 14 [10-17]% 201T1 defect, p = 0.001) and predischarge LVESVi (45% [40 to 52] vs. 30% [29 to 38] mL/m2, p = 0.001) were larger, and LV ejection fraction at six weeks (40% [37 to 46] vs. 55% [50 to 60], p = 0.004) was lower in patients with RS than in patients without RS. CONCLUSIONS: Patients with RS during primary PTCA for an anterior AMI have a transiently lower CVR than patients without RS, but sustained LV dysfunction and larger infarct size, suggesting that RS is a marker of microcirculatory reperfusion injury.     

Predictive value of markers of myocardial reperfusion in acute myocardial infarction for follow-up left ventricular function

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty (PTCA) for first AMI, and intravenous MCE was determined before, and at 1 and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE 1 hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p <0.001) and was in an analysis of variance the best parameter to predict GWMI 4 weeks after AMI. The ST-segment elevation index was close in its predictive value. Considering only invasive parameters of reperfusion myocardial blush grade was the best predictor of GWMI at 4 weeks (R² = 0.3107, p <0.001). A MCE perfusion defect size at 24 hours of ≥50% of the MCE perfusion defect size before PTCA was used to define myocardial nonreperfusion. In a multivariate analysis, low myocardial blush grade class was the best predictor of nonreperfusion defined by MCE. Thus, intravenous MCE allows better prediction of left ventricular function 4 weeks after AMI than other evaluated parameters of myocardial reperfusion. Myocardial blush grade is the best predictor of nonreperfusion defined by MCE and is the invasive parameter with the greatest predictive value for left ventricular function after AMI. Coronary flow parameters are less predictive.     

An Approach to the Rational Use of Revascularization in Heart Failure Patients

The most common cause of heart failure with reduced ejection fraction (HFrEF) is coronary artery disease. A multitude of factors come into play when deciding whether a patient with HFrEF and coronary artery disease should have coronary artery bypass graft (CABG) surgery, percutaneous coronary intervention, or medical therapy alone. For candidates for percutaneous coronary intervention and CABG, evidence from large registries would suggest that patients with 2-vessel coronary artery diseases and proximal left anterior descending disease and all patients with 3-vessel coronary artery disease do better with CABG. For patients that are candidates for medical therapy with or without CABG, the results of the Surgical Treatment for Ischemic Heart Failure (STICH) trial indicate that with CABG, the reduction of mortality is not statistically significant (hazard ratio [HR], 0.86; P = 0.12). However, CABG is superior in reducing cardiovascular deaths (HR, 0.81; P = 0.05), and the combination of cardiovascular deaths and cardiovascular hospitalizations (HR, 0.74; P < 0.001). Patients undergoing CABG have an upfront risk that is eliminated by 2 years and thereafter do better. The assessment of cardiac viability or reversible ischemia does not appear to be helpful in determining which individuals will improve more with CABG. Patients with severe mitral regurgitation who undergo CABG appear to benefit from simultaneous valve repair but not from the addition of surgical ventricular reconstruction of the left ventricle, although in specific patients this might be considered. The totality of evidence would thus suggest that patients with HFrEF should be evaluated for the possibility of coronary revascularization if they are candidates for CABG.