Victoria Bernstein

Sex Differences in the Management of Coronary Artery Disease

BACKGROUND Despite the fact that coronary artery disease is the leading cause of death among women, previous studies have suggested that physicians are less likely to pursue an aggressive approach to coronary artery disease in women than in men. To define this issue further, we compared the care previously received by men and women who were enrolled in a large postinfarction intervention trial. METHODS We assessed the nature and severity of anginal symptoms and the use of antianginal and antiischemic interventions before enrollment in the 1842 men and 389 women with left ventricular ejection fractions less than or equal to 40 percent after an acute myocardial infarction who were randomized in the Survival and Ventricular Enlargement trial. RESULTS Before their index infarction, women were as likely as men to have had angina and to have been treated with antianginal drugs. However, despite reports by women of symptoms consistent with greater functional disability from angina, fewer women had undergone cardiac catheterization (15.4 percent of women vs. 27.3 percent of men, P less than 0.001) or coronary bypass surgery (5.9 percent of women vs. 12.7 percent of men, P less than 0.001). When these differences were adjusted for important covariates, men were still twice as likely to undergo an invasive cardiac procedure as women, but bypass surgery was performed with equal frequency among the men and women who did undergo cardiac catheterization. CONCLUSIONS Physicians pursue a less aggressive management approach to coronary disease in women than in men, despite greater cardiac disability in women.

Sphygmomanometrically Determined Pulse Pressure Is a Powerful Independent Predictor of Recurrent Events After Myocardial Infarction in Patients With Impaired Left Ventricular Function

BACKGROUND There is increasing evidence of a link between conduit vessel stiffness and cardiovascular events, although the association has never been tested in a large post-myocardial infarction patient population. METHODS AND RESULTS We evaluated the relationship between baseline pulse pressure, measured by sphygmomanometry 3 to 16 days after myocardial infarction, and subsequent adverse clinical events in the 2231 patients enrolled in the SAVE Trial. Increased pulse pressure was associated with increased age, left ventricular ejection fraction, female sex, history of prior infarction, diabetes, and hypertension and use of digoxin and calcium channel blockers. Over a 42-month period, there were 503 deaths, 422 cardiovascular deaths, and 303 myocardial infarctions. Pulse pressure was significantly related to each of these end points as a univariate predictor. In a multivariate analysis, pulse pressure remained a significant predictor of total mortality (relative risk, 1.08 per 10 mm Hg increment in pulse pressure; 95% CI, 1.00 to 1.17; P<.05) and recurrent myocardial infarction (relative risk, 1.12; 95% CI, 1.01 to 1.23; P<.05) after control for age; left ventricular ejection fraction; mean arterial pressure; sex; treatment arm (captopril or placebo); smoking history; history of prior myocardial infarction, diabetes, or hypertension; and treatment with beta-blockers, calcium channel blockers, digoxin, aspirin, or thrombolytic therapy. CONCLUSIONS These data provide strong evidence for a link between pulse pressure, which is related to conduit vessel stiffness, and subsequent cardiovascular events after myocardial infarction in patients with left ventricular dysfunction.

Reduction of Stroke Incidence After Myocardial Infarction With Pravastatin The Cholesterol and Recurrent Events (CARE) Study

BACKGROUND The role of lipid modification in stroke prevention is controversial, although increasing evidence suggests that HMG-CoA reductase inhibition may reduce cerebrovascular events in patients with prevalent coronary artery disease. METHODS AND RESULTS To test the hypothesis that cholesterol reduction with pravastatin may reduce stroke incidence after myocardial infarction, we followed 4159 subjects with average total and LDL serum cholesterol levels (mean, 209 and 139 mg/dL, respectively) who had sustained an infarction an average of 10 months before study entry and who were randomized to pravastatin 40 mg/d or placebo in the Cholesterol and Recurrent Events (CARE) trial. Using prospectively defined criteria, we assessed the incidence of stroke, a prespecified secondary end point, and transient ischemic attack (TIA) over a median 5-year follow-up period. Patients were well matched for stroke risk factors and the use of antiplatelet agents (85% of subjects in each group). Compared with placebo, pravastatin lowered total serum cholesterol by 20%, LDL cholesterol by 32%, and triglycerides by 14% and raised HDL cholesterol by 5% over the course of the trial. A total of 128 strokes (52 on pravastatin, 76 on placebo) and 216 strokes or TIAs (92 on pravastatin, 124 on placebo) were observed, representing a 32% reduction (95% CI, 4% to 52%, P=0.03) in all-cause stroke and 27% reduction in stroke or TIA (95% CI, 4% to 44%, P=0.02). All categories of strokes were reduced, and treatment effect was similar when adjusted for age, sex, history of hypertension, cigarette smoking, diabetes, left ventricular ejection fraction, and baseline total, HDL, and LDL cholesterol and triglyceride levels. There was no increase in hemorrhagic stroke in patients on pravastatin compared with placebo (2 versus 6, respectively). CONCLUSIONS Pravastatin significantly reduced stroke and stroke or TIA incidence after myocardial infarction in patients with average serum cholesterol levels despite the high concurrent use of antiplatelet therapy.

A comparison of management patterns after acute myocardial infarction in Canada and the United States

BACKGROUND There are major differences in the organization of the health care systems in Canada and the United States. We hypothesized that these differences may be accompanied by differences in patient care. METHODS To test our hypothesis, we compared the treatment patterns for patients with acute myocardial infarction in 19 Canadian and 93 United States hospitals participating in the Survival and Ventricular Enlargement (SAVE) study, which tested the effectiveness of captopril in this population of patients after a myocardial infarction. RESULTS In Canada, 51 percent of the patients admitted to a participating coronary care unit had acute myocardial infarctions, as compared with only 35 percent in the United States (P < 0.001). Despite the similar clinical characteristics of the 1573 U.S. patients and 658 Canadian patients participating in the study, coronary arteriography was more commonly performed in the United States than in Canada (in 68 percent vs. 35 percent, P < 0.001), as were revascularization procedures before randomization (31 percent vs. 12 percent, P < 0.001). During an average follow-up of 42 months, these procedures were also performed more commonly in the United States than in Canada. These differences were not associated with any apparent difference in mortality (22 percent in Canada and 23 percent in the United States) or rate of reinfarction (14 percent in Canada and 13 percent in the United States), but there was a higher incidence of activity-limiting angina in Canada than in the United States (33 percent vs. 27 percent, P < 0.007). CONCLUSIONS The threshold for the admission of patients to a coronary care unit or for the use of invasive diagnostic and therapeutic interventions in the early and late periods after an infarction is higher in Canada than in the United States. This is not associated with any apparent difference in the rate of reinfarction or survival, but is associated with a higher frequency of activity-limiting angina.

Prognostic value of neurohumoral activation in patients with an acute myocardial infarction: effect of captopril.

OBJECTIVES This study attempted to evaluate whether neurohumoral activation at the time of hospital discharge in postinfarction patients helps to predict long-term prognosis and whether long-term therapy with the angiotensin-converting enzyme inhibitor captopril modifies this relation. BACKGROUND Neurohumoral activation persists at the time of hospital discharge in a large number of postinfarction patients. The Survival and Ventricular Enlargement (SAVE) study demonstrated that the angiotensin-converting enzyme inhibitor captopril improves survival and decreases the development of severe heart failure in patients with left ventricular dysfunction (left ventricular ejection fraction < or = 40%) but no overt postinfarction heart failure. METHODS In 534 patients in the SAVE study, plasma neurohormone levels were measured a mean of 12 days after infarction. Patients were then randomized to receive captopril or placebo and were followed up for a mean (+/- SD) of 38 +/- 6 months (range 24 to 55). The association between activation of plasma neurohormones at baseline and subsequent cardiovascular mortality or the development of heart failure was assessed with and without adjustment for other important prognostic factors. RESULTS By univariate analysis, activation of plasma renin activity and aldosterone, norepinephrine, atrial natriuretic peptide and arginine vasopressin levels were related to subsequent cardiovascular events, whereas epinephrine and dopamine levels were not. By multivariate analysis, only plasma renin activity (relative risk 1.6, 95% confidence interval [CI] 1.0 to 2.5) and atrial natriuretic peptide (relative risk 2.2, 95% CI 1.3 to 3.8) were independently predictive of cardiovascular mortality, whereas the other neurohormones were not. Only plasma renin activity and aldosterone, atrial natriuretic peptide and arginine vasopressin were independent predictors of the combined end points of cardiovascular mortality, development of severe heart failure or recurrent myocardial infarction. Except for 1-year cardiovascular mortality, the use of captopril did not significantly modify these relations. CONCLUSIONS Neurohumoral activation at the time of hospital discharge in postinfarction patients is an independent sign of poor prognosis. This is particularly true for plasma renin activity and atrial natriuretic peptide. Except for 1-year cardiovascular mortality, captopril does not significantly modify these relations.

Activation of neurohumoral systems in postinfarction left ventricular dysfunction

OBJECTIVES This study was conducted to evaluate the degree of neurohumoral activation around the time of hospital discharge after myocardial infarction. BACKGROUND Because pharmacologic interventions that block the effects of neurohumoral activation improve the prognosis after infarction, we hypothesized that widespread neurohumoral activation persists in some patients until at least the time of hospital discharge and that the determinants of activation vary from one system to another. METHODS Five hundred nineteen patients in the Survival and Ventricular Enlargement Study (SAVE) had plasma neurohormones measured before randomization at a mean of 12 days after infarction. All patients had left ventricular dysfunction (left ventricular ejection fraction < or = 40%) but no overt heart failure. RESULTS Although all neurohormones except epinephrine were increased compared with values in age-matched control subjects, plasma norepinephrine (301 +/- 193 vs. 222 +/- 87 pg/ml, p < 0.001), renin activity (3.0 +/- 3.7 vs. 1.2 +/- 1.2 ng/ml per h, p < 0.001), arginine vasopressin (1.9 +/- 6.9 vs. 0.7 +/- 0.3 pg/ml, p < 0.001) and atrial natriuretic peptide (75 +/- 75 vs. 21 +/- 9 pg/ml, p < 0.001) values ranged from normal to very high, indicating a wide spectrum of neurohumoral activation. Activation of one system did not correlate with activation of another. The clinical and laboratory variables most closely associated with neurohumoral activation were Killip class, left ventricular ejection fraction, age and use of diuretic drugs. The association between neurohumoral activation and clinical and laboratory variables varied from one neurohormone to another. CONCLUSIONS Neurohumoral activation occurs in a significant proportion of patients at the time of hospital discharge after infarction. Which neurohormone is activated and which clinical and laboratory variables determine this activation vary from one neurohormone to another.

Activation of neurohumoral systems following acute myocardial infarction

Previous studies have indicated that patients with an acute myocardial infarction have marked activation of all neurohumoral systems on admission to the hospital. This activation begins to subside within the first 72 hours so that by 7-10 days, all plasma neurohormones have returned to normal. The only documented exceptions were found to occur in patients with left ventricular dysfunction and overt heart failure, where both plasma renin activity and atrial natriuretic peptide were increased, and in patients with left ventricular dysfunction but no overt heart failure, where only atrial natriuretic peptide was increased. Although these studies suggest that neurohumoral activation rarely occurs at the time of hospital discharge, they were small and may have missed an important subgroup of patients with persistent neurohumoral activation. In the Survival and Ventricular Enlargement (SAVE) study, 522 patients had plasma neurohumoral levels measured at a mean of 12 days postinfarction. All SAVE patients had left ventricular dysfunction (left ventricular ejection fraction less than or equal to 40%), but no overt heart failure. In this group of patients, all neurohumoral levels (plasma renin activity, norepinephrine, arginine vasopressin, and atrial natriuretic peptide) were found to be increased compared with age-matched control subjects. These results indicate that, in fact, a subgroup of patients without overt heart failure has persistent neurohumoral activation at the time of hospital discharge postinfarction, and that this activation involves several neurohumoral systems. Since patients with persistent neurohumoral activation postinfarction are likely those most at risk of developing complications and the ones most likely to benefit from pharmacologic interventions blunting the effects of neurohumoral activation, measurement of predischarge neurohumoral levels may be useful.

Prophylactic Intravenous Magnesium Sulphate in Addition to Oral β-Blockade Does Not Prevent Atrial Arrhythmias After Coronary Artery or Valvular Heart Surgery

Background— Atrial arrhythmias (AA) are an important cause of morbidity after cardiac surgery. Efforts at prevention of postoperative AA have been suboptimal. Perioperative beta-blocker administration is the standard of care at many centers. Although prophylactic administration of magnesium sulfate (MgSO4) has been recommended, review of all previously published trials of MgSO4 reveals conflicting results. This study was designed to address methodological shortcomings from previous studies and is the largest randomized, placebo-controlled trial of intravenous (IV) MgSO4 for the prevention of AA after coronary artery bypass grafting or cardiac valvular surgery. Methods and Results— A total of 927 nonemergent cardiac surgery patients were stratified into 2 groups: isolated coronary artery bypass grafting (n=694), or valve surgery with or without coronary artery bypass grafting (n=233), and randomized to receive either 5g IV MgSO4 or placebo on removal of the cross-clamp, followed by daily 4-hour infusions, from postoperative day 1 until postoperative day 4. All patients were treated according to an established oral &bgr;-blocker protocol. Postoperative serum Mg levels were checked and standard of care was to administer IV MgSO4 for low serum levels. The primary end point was AA lasting ≥30 minutes or requiring treatment for hemodynamic compromise. There were no differences in the incidence of AA between patients who received IV MgSO4 or placebo (26.4% versus 24.3%, respectively). The results were similar when broken down according to stratified groups. Conclusions— In patients treated with a protocol for postoperative oral &bgr;-blocker after nonemergent cardiac surgery, the addition of prophylactic IV MgSO4 did not reduce the incidence of AA.

Ticagrelor and aspirin for the prevention of cardiovascular events after coronary artery bypass graft surgery

Background Ticagrelor was shown to reduce mortality in patients who underwent coronary artery bypass grafting (CABG), but its effect on graft patency is unknown. Methods We performed a prospective, randomised, double-blind, placebo-controlled trial, comparing ticagrelor 90 mg twice daily versus placebo for 3 months added to aspirin 81 mg/day, following isolated CABG. Aspirin was started within 12 h, and study medication within 72 h after CABG. Primary outcome was graft occlusion on CT angiography (CTA) performed 3 months post CABG. Patients were followed to 12 months for death, myocardial infarction, stroke, repeat revascularisation and bleeding. Results The study was terminated prematurely after randomising 70 patients between September 2011 and August 2014 because of slow recruitment. CTA was performed in 56 patients who completed >1 month of study drug. Graft occlusion occurred in 7/25 (28.0%) patients on ticagrelor and 17/31 (48.3%) on placebo, p=0.044. Of 207 analysable grafts, graft occlusion occurred in 9/87 (10.3%) with ticagrelor and 22/120 (18.3%) with placebo, p=0.112. Graft occlusion or stenosis ≥50% occurred in 10/87 (11.5%) ticagrelor vs 32/120 (26.7%) placebo, p=0.007. There was no major bleeding, but minor bleeding was higher with ticagrelor (31.4% vs 2.9%, p=0.003). In univariate analysis, ticagrelor use reduced graft occlusion (OR 0.32, 95% CI 0.10 to 0.97, p=0.047), which remained significant on multivariable analysis (OR 0.25, 95% CI 0.073 to 0.873, p=0.03). Conclusions Ticagrelor added to aspirin after CABG reduced the proportion of patients with graft occlusion, and was a significant univariate and multivariable predictor of graft occlusion. These results are hypothesis-generating and should be confirmed in larger studies. Trial registration number NCT01373411: Results.

Investigation of the Relationship between Lecithin:Cholesterol Acyltransferase Activity and Coronary Atheroma, Diagnosed by Selective Coronary Angiography

140 consecutive patients undergoing selective coronary angiography in the investigation of chest pain had fasting blood specimens collected. 24 specimens were unsuitable due to hemolysis or to incomplete coronary angiography studies. In the 116 remaining patients the serum was analyzed for total cholesterol, free cholesterol, and the initial rate of cholesterol esterification. LCAT activity was determined both as the percentage esterification per minute, and as nmols/ml/min. All the coronary angiograms were examined by a single cardiologist who was unaware of the results of the serum tests. Fixed predetermined criteria were used, resulting in all patients being classified as one of four groups. 36 patients had no detectable atheroma, 23 mild, 21 moderate, and 36 severe. Statistical analysis revealed a significant relationship between the presence and severity of coronary atheroma with the patients age, and an equally strong relationship was found with the patients total serum cholesterol. No statistically valid correlation could be found between LCAT activity (as determined by esterification in the patients native serum) and atheroma. Free cholesterol levels also did not correlate with the presence of antheroma. An interesting finding was the presence of severe antheroma in a small number of patients with low normal level of serum cholesterol and high LCAT activity.