Dov Freimark

Prognostic significance of mild mitral regurgitation by color Doppler echocardiography in acute myocardial infarction

Mitral regurgitation (MR) complicating acute myocardial infarction (AMI) is associated with increased mortality. The prognostic significance of only mild MR detected by echocardiography in patients with AMI is unknown. This study assessed the long-term risk associated with mild MR detected by color Doppler echocardiography within the first 48 hours of admission in 417 consecutive patients with AMI. No MR was detected in 271 patients (65%), mild MR was seen in 121 patients (29%), and moderate or severe MR was noted in 25 patients (6%). One-year mortality rates were 4.8%, 12.4%, and 24%, respectively (p<0.001). Multivariate analysis revealed that mild MR was independently associated with increased 1-year mortality (p<0.05) after adjustment for age, gender, previous myocardial infarction, diabetes mellitus, systemic hypertension, Killip grade > or =2 on admission, and left ventricular ejection fraction < or =40%. The hazard ratio for 1-year mortality was 2.31 (95% confidence interval 1.03 to 5.20) for mild MR and 2.85 (95% confidence interval 0.95 to 8.51) for moderate or severe MR. Thus, mild MR detected by color Doppler echocardiography within the first 2 days of admission in patients with AMI is a significant independent risk predictor for 1-year all-cause mortality.

Outcome of myocardial infarction in patients treated with aspirin is enhanced by pre-hospital administration.

Objective: Reducing time to reperfusion therapy is one of the goals in the management of acute myocardial infarction (AMI). We assessed the association between timing of aspirin administration and outcome of patients with AMI. Patients: We studied 922 consecutive AMI patients with ST-segment elevation in Killip class I–III on admission. Patients were divided into two groups based upon the timing of emergency aspirin administration: before (early aspirin users) or after (late aspirin users) hospital admission. Results: Early aspirin users (n = 338; 37%) were younger, less likely to be women, and more likely to smoke (p < 0.006) than late users (n = 584; 63%). Other baseline and clinical characteristics were similar. Early aspirin users were more likely to be treated with thrombolysis or primary percutaneous transluminal coronary angioplasty. Compared with late users, early aspirin users had significantly lower in-hospital complications and lower mortality rates at 7 (2.4 vs. 7.3%, p = 0.002) and 30 days (4.9 vs. 11.1%, p = 0.001). By multivariate adjustment, pre-hospital aspirin was an independent determinant of survival at 7 (odds ratio 0.43; 95% confidence interval 0.18–0.92) and at 30 days (odds ratio, 0.60; 95% confidence interval 0.32–1.08). Survival benefit associated with aspirin persisted for subgroups treated or not with reperfusion therapy. Conclusions: Outcome of AMI patients treated with aspirin is improved by pre-hospital administration.Our findings suggest that emergency pre-hospital aspirin might facilitate early reperfusion.

Timing of aspirin administration as a determinant of survival of patients with acute myocardial infarction treated with thrombolysis.

Unlike thrombolytic agents, there are conflicting data regarding the time-dependent effect of aspirin treatment on outcome in acute myocardial infarction (AMI). We sought to evaluate the impact of timing of aspirin administration (before vs after thrombolysis) on mortality of patients with AMI. Our study included 1,200 patients with ST elevation AMI treated with thrombolysis. Early (n = 364) versus late (n = 836) users were defined as those receiving emergency aspirin before versus after initiation of thrombolysis, respectively. Time (median) from symptom onset to initiation of aspirin treatment was significantly shorter in early versus late users (1.6 vs 3.5 hours; p <0.001). There were no significant differences between the 2 groups with respect to baseline clinical characteristics. Early aspirin users were more likely to develop reischemia, to be treated with beta blockers, to be referred to coronary angiography, percutaneous transluminal coronary angioplasty, or coronary artery bypass graft surgery. Early users experienced lower mortality at 7 days (2.5% vs 6.0%, p = 0.01), 30 days (3.3% vs 7.3%, p = 0.008), and 1 year (5.0% vs 10.6%, p = 0.002) than late users. This survival benefit persisted for patients with and without previous aspirin therapy or revascularization and after adjustment for baseline characteristics and therapies at 7 days (odds ratio 0.36, 95% confidence interval 0.15 to 0.79), at 30 days (odds ratio 0.39, 95% confidence interval 0.17 to 0.82), and at 1 year (odds ratio 0.41, 95% confidence interval 0.21 to 0.74). Our study proposes a time-dependent benefit from aspirin in patients with AMI treated with thrombolysis.

Significance of ST segment elevations in posterior chest leads (V7 to V9) in patients with acute inferior myocardial infarction: application for thrombolytic therapy.

OBJECTIVESnThis study was designed to examine whether ST segment elevation in posterior chest leads (V7 to V9) during acute inferior myocardial infarction (MI) identifies patients with a concomitant posterior infarction and whether these patients might benefit more from thrombolysis.nnnBACKGROUNDnBecause the posterior wall is faced by none of the 12 standard electrocardiographic (ECG) leads, the ECG diagnosis of posterior infarction is problematic and has often remained undiagnosed, especially in the acute phase.nnnMETHODSnEighty-seven patients with a first inferior infarction who were treated with recombinant tissue-type plasminogen activator were stratified according to the presence (Group A [46 patients]) or absence (Group B [41 patients]) of concomitant ST segment elevation in posterior chest leads V7 to V9.nnnRESULTSnPatients in Group A had a higher incidence of posterolateral wall motion abnormalities (p < 0.001) on radionuclide ventriculography, a larger infarct area (as evidenced by higher peak creatine kinase levels) (p < 0.02) and a lower left ventricular ejection fraction (LVEF) at hospital discharge (p < 0.008) than those in Group B. ST segment elevation in leads V7 to V9 was associated with a higher incidence of at least one of the following adverse clinical events: reinfarction, heart failure or death (p = 0.05). Although patency of the infarct-related artery (IRA) in Group A resulted in an improved LVEF at discharge (p < 0.012), LVEF was unchanged in Group B, regardless of the patency status of the IRA.nnnCONCLUSIONSnST segment elevation in leads V7 to V9 identifies patients with a larger inferior MI because of concomitant posterolateral involvement. Such patients might benefit more from thrombolytic therapy.

Functional class in patients with heart failure is associated with the development of diabetes

PURPOSEnRecent reports suggest that decreased functional capacity in patients with heart failure may be associated with abnormalities in glucose metabolism. We followed patients with coronary artery disease who participated in the Bezafibrate Infarction Prevention study to determine the incidence of diabetes by baseline functional status during a 7.7-year follow-up.nnnMETHODSnThe sample comprised 2616 nondiabetic patients aged 45 to 74 years with a fasting blood glucose level <7 mmol/L (126 mg/dL). They were divided into three groups by New York Heart Association (NYHA) criteria: class I (n = 1986 patients), class II (n = 518), and class III (n = 112). The detection of a fasting blood glucose level > or =7 mmol/L during follow-up was defined as the criterion for the development of diabetes.nnnRESULTSnThe study groups had similar demographic and clinical characteristics, except that patients with symptomatic heart failure (NYHA class II or III) were more likely to have angina. During follow-up, diabetes developed in 259 patients (13%) in NYHA class I, 76 (15%) in class II, and 22 (20%) in class III (P for trend = 0.05). At the last visit, patients in NYHA class III were twice as likely (17% [n = 19]) to have fasting blood glucose levels > or =7 mmol/L as those in NYHA class I (7.8% [n = 154]) or class II (8.7% [n = 45]) (P = 0.005). In a multivariate analysis, NYHA class III was associated with a 1.7-fold (95% confidence interval [CI]: 1.1 to 2.6) increase in the rate of development of diabetes, but NYHA class II was not (hazard ratio = 1.0; 95% CI: 0.8 to 1.3).nnnCONCLUSIONnAmong patients with coronary artery disease, advanced heart failure (NYHA class III) is associated with a significantly increased risk of developing diabetes during a 6- to 9-year follow-up.

The distinction between coronary and myocardial reperfusion after thrombolytic therapy by clinical markers of reperfusion.

OBJECTIVESnWe sought to examine the hypothesis that rapid resolution of ST-segment elevation in acute myocardial infarction (AMI) patients with early peak creatine kinase (CK) after thrombolytic therapy differentiates among patients with early recanalization between those with and those without adequate tissue (myocardial) reperfusion.nnnBACKGROUNDnEarly recanalization of the epicardial infarct-related artery (IRA) during AMI does not ensure adequate reperfusion on the myocardial level. While early peak CK after thrombolysis results from early and abrupt restoration of the coronary flow to the infarcted area, rapid ST-segment resolution, which is another clinical marker of successful reperfusion, reflects changes of the myocardial tissue itself.nnnMETHODSnWe compared the clinical and the angiographic results of 162 AMI patients with early peak CK (< or =12 h) after thrombolytic therapy with (group A) and without (group B) concomitant rapid resolution of ST-segment elevation.nnnRESULTSnPatients in groups A and B had similar patency rates of the IRA on angiography (anterior infarction: 93% vs. 93%; inferior infarction: 89% vs. 77%). Nevertheless, group A versus B patients had lower peak CK (anterior infarction: 1,083+/-585 IU/ml vs. 1,950+/-1,216, p < 0.01; and inferior infarction: 940+/-750 IU/ml vs. 1,350+/-820, p=0.18) and better left ventricular ejection fraction (anterior infarction: 49+/-8, vs. 44+/-8, p < 0.01; inferior infarction: 56+/-12 vs. 51+/-10, p=0.1). In a 2-year follow-up, group A as compared with group B patients had a lower rate of congestive heart failure (1% vs. 13%, p < 0.01) and mortality (2% vs. 13%, p < 0.01).nnnCONCLUSIONSnAmong patients in whom reperfusion appears to have taken place using an early peak CK as a marker, the coexistence of rapid resolution of ST-segment elevation further differentiates among patients with an opened culprit artery between the ones with and without adequate myocardial reperfusion.

Improvement of Congestive Heart Failure by Upgrading of Conventional to Resynchronization Pacemakers

Aims: To compare the clinical response of patients with right ventricular apical pacing (RVAP) upgraded to cardiac resynchronization therapy (CRT) to that of previously nonpaced heart failure (HF) patients who had de novo CRT implantation.

A Novel Titin Mutation in Adult-Onset Familial Dilated Cardiomyopathy

Familial dilated cardiomyopathy is a major cause of advanced heart failure and heart transplantation. In most families, the disease-causing mutation is unknown, and relatives should therefore undergo periodic screening to facilitate early diagnosis and therapy. In the present study, we describe a novel titin truncation mutation causing adult-onset familial dilated cardiomyopathy in an Israeli Arab family. The family members underwent physical examination, electrocardiography, and Doppler echocardiography. Linkage to candidate loci was performed, followed by gene sequencing. We identified 13 clinically affected family members (8 men and 5 women, mean age 47 ± 12 years). Compared with their healthy first-degree relatives, the affected relatives had a larger end-diastolic left ventricular dimension (60 ± 10 vs 49 ± 4 mm, p <0.001), lower ejection fraction (43 ± 11% vs 60 ± 6%, p <0.001), and markedly higher end-systolic volume indexes but no difference in wall thickness or diastolic function. The linkage studies or direct sequencing excluded LMNA, MYH7, TNNT2, TNNI3, SCN5A, DES, SGCD, ACTC, PLN, and MYH6 but established linkage to the TTN locus at chromosome 2q31, yielding a maximum (2-point) LOD score of 3.44. Sequence analysis identified an insertion (c.58880insA), causing protein truncation after 19,628 amino acids (p.S19628IfsX1). No founder effect was found among the Israeli Arabs. In conclusion, titin is a giant protein with a key role in sarcomere assembly, force transmission, and maintenance of resting tension. Although some mutations result in skeletal myopathy, others cause isolated, maturity-onset cardiomyopathy.

Increased glycogen stores due to γ-AMPK overexpression protects against ischemia and reperfusion damage

During ischemia, endogenous glycogen becomes the principal substrate for energy through glycolysis. Cardiac-specific manipulation of AMP-activated protein kinase (AMPK) by over-expression of its regulatory gamma-subunit induces glycogen storage. The aim of this study was to examine whether heart glycogen in transgenic mice overexpressing PRKAG2 may protect from ischemia and reperfusion injury. Isolated hearts were mounted on Langendorff apparatus and subjected to 30 min no-flow or low-flow ischemia and 60 min reperfusion. Hemodynamic measurements, tetrazolium staining, glycogen and lactate were used to monitor ischemia reperfusion damage. After low-flow ischemia, left ventricular pressure, coronary flow (CF) and the area of viable myocardium were 20-30% higher in PRKAG2 mice compared to controls. The basal levels of glycogen in PRKAG2 were 9.2 microg/g, markedly higher than in controls, but after low-flow ischemia they declined concomitantly with increased lactate washout in the coronary effluent. During no-flow ischemia there was neither protection nor consumption of glycogen in PRKAG2 hearts. Cardioprotection was also eliminated when PRKAG2 hearts were depleted of glycogen prior to low-flow ischemia. AMPK alpha Thr172 phosphorylation did not differ between PRKAG2 hearts and controls either during low-flow ischemia or reperfusion. We conclude that PRKAG2 hearts resist low-flow ischemia injury better than controls. Improved recovery was associated with increased consumption of glycogen, and was unrelated to AMPK activation. These findings demonstrate the potential of heart protection from ischemia and reperfusion injury through metabolic manipulation increasing the level and utilization of myocardial glycogen.

Effect of Elevated Homocysteine Levels on Clinical Restenosis following Percutaneous Coronary Intervention

Since hyperhomocysteinemia confers a prothrombotic effect and promotes proliferation of smooth muscle cells in response to vascular injury, it might be implicated in the pathogenesis of restenosis after percutaneous coronary intervention (PCI). Our study comprised 55 patients who underwent successful PCI in the acute myocardial infarction (AMI) course. Homocysteine levels were determined within 24 h of admission. During a 1-year follow-up, 16 patients (31%) underwent repeated coronary angiography for recurrent angina or re-infarction, which demonstrated re-narrowing of ≧50% at the qualifying PCI site (clinical restenosis). Irrespective of stent deployment, clinical restenosis was not associated with higher homocysteine levels (12 ± 7 vs. 14 ± 11µmol/l, p = 0.77). There was no correlation between homocysteine levels and time to restenosis (r2 = 0.06, p = 0.35). In conclusion, elevated homocysteine levels do not predict a higher incidence of restenosis after PCI.