Risk Of Recurrent Cardiac Events Research Articles

Enhancing Outcomes of Acute Coronary Syndromes

Objective: The objectives of the initial evaluation of patients with nontraumatic chest pain are 2-fold: 1) to assess the probability that the patient's symptoms are related to acute coronary ischemia; and 2) to assess the patient's risk of recurrent cardiac events, including death and recurrent ischemia. When applied in conjunction with the clinical history, physical examination, and interpretation of the electrocardiogram, cardiac biomarkers are valuable in achieving both of these objectives. The most urgent priority of early evaluation is to identify patients with acute myocardial infarction (AMI) who should be considered for immediate reperfusion therapy and to recognize other potentially catastrophic causes of sudden patient decompensation such as aortic dissection. GOALS OF THE ACUTE CORONARY SYNDROME INITATIVE Improvement in turnaround times for cardiac injury markers (vein to brain) <30 minutes from order to physician notification Safely impact length of stay (LOS) in the emergency department (ED) Improve ED patient disposition: appropriate discharges from the ED versus admissions Enhance ED patient placement: clinical decision unit (CDU), intensive care unit (ICU), cardiac telemetry Impact patient outcomes: appropriate risk stratification of patients with ACS and AMI NEXT STEPS Addition of POC connectivity, which will further impact turn-around-time (TAT) by automating the ordering process (currently a manual process on Meditech) Submission process for HCA-Clinical Cardiovascular Management Network (CCMN); Cardiovascular Centers of Merit Program Prepare for Society of Chest Pain Centers reaccreditation Pursue a stroke initiative for West Houston Medical Center Pursue a similar process for a congestive heart failure (CHF) initiative Continue to foster multidisciplinary communication Continue to enhance key ACS quality initiatives Patient satisfaction ACS outcomes Cost of care/ROI Continue to elevate compliance to CMS AMI core measures CONCLUSIONS The foundation for successful outcomes begins with ACS disease process education from various multidisciplinary perspectives. Point of Care (POC) testing and ACS process redesign is a journey that must include a multidisciplinary team to be successful. Accurate, earlier diagnostic results favorably impacts both quality and cost. A patient-centric improvement effort must be the shared vision of both internal and external resources (ie, vendor partnership and emergency medical services) to be successful. This template may provide an avenue for future disease state management initiatives. TABLE 1: Process and Timeline Results: Outcomes Pre- and Post-Point of Care Cardiac Testing (POCT)

Psychological interventions for depression in heart failure.

Heart failure is a common and growing health problem. Depression is prevalent among these patients and is associated with an increased risk of mortality, in some, but not all, studies. Depression may increase the risk of recurrent cardiac events and death, either through direct pathophysiological mechanisms such as thrombogenesis or ventricular arrhythmias, or through behavioural mechanisms. Depressed patients are less likely to adhere to their medication regimen and modify their lifestyle appropriately, thereby increasing the likelihood of recurrent cardiac events and death. The effects of psychological interventions for depression in terms of reducing depression and improving prognosis in patients with heart failure are unknown. To assess the effects of psychological interventions for depression in people with heart failure on depression and quality of life, morbidity, and mortality in these patients. We searched the Cochrane Central Register of Controlled Trials and The Database of Abstracts of Reviews of Effects on The Cochrane Library (Issue 3, 2003), MEDLINE (1951 to August 2003), PsycINFO (1887 to August 2003), CINAHL (1980 to August 2003) and EMBASE (1980 to August 2003). Searches of reference lists of retrieved papers were also made and expert advice was sought. Abstracts from national and international cardiology, psychology, and psychiatry conferences in 2003 and dissertation abstracts were also searched. All relevant foreign language papers were translated. RCTs of psychological interventions for depression in adults (18 years or older) with heart failure. The primary outcome was a significant reduction in depression. The secondary outcomes were the acceptability of treatment, quality of life, cardiac morbidity (hospital re-admission for heart failure and non-fatal cardiovascular events), reduction of cardiovascular behavioural risk factors, health economics, and death. Two reviewers independently screened titles and abstracts of potential studies. Two reviewers independently assessed the full papers for inclusion criteria. Further information was sought from the authors where papers contained insufficient information to make a decision about eligibility. No RCTs of psychological interventions for depression in patients with heart failure were identified. Depression is common among patients with heart failure. Randomised controlled trials of psychological interventions for depression in heart failure patients are needed to investigate the impact of such interventions on depression, quality of life, behavioural CVD risk factors, cardiac morbidity, health economics and mortality, given the paucity of such trials in this area and the increasing prevalence of heart failure.

Plasma markers of endothelial damage/dysfunction, inflammation and thrombogenesis in relation to TIMI risk stratification in acute coronary syndromes

Risk stratification at presentation with acute coronary syndromes (ACS) on the basis of the TIMI risk score for unstable angina and non-ST-elevation myocardial infarction (UAP/NSTEMI) identifies patients at high risk of recurrent cardiac events and those who benefit from more aggressive treatment strategy. We hypothesised the following: (a) that a high TIMI risk score brings a greater degree of acute changes in endothelial damage/dysfunction (circulating endothelial cells [CECs], von Willebrand factor [vWf]), inflammation (interleukin-6, IL-6) and blood thrombogenicity (plasma tissue factor, TF); and (b) that these indices are higher in those with high TIMI risk score who experienced recurrent cardiac event at day 14 and day 30. TIMI risk scores were determined at admission and 48 hours later in 88 ACS patients (60 male, age 67+/-12 yrs) with UAP or NSTEMI. CECs, IL-6 and TF levels were measured at both time points and the acute change (delta) calculated. Patients were split into high (score > or =4) or low (<4) TIMI score groups. The composite end point of death, myocardial infarction, and refractory angina requiring revascularisation following 14 and 30 days' follow-up was ascertained. Fifty-eight patients with high TIMI risk score (mean 4.7) had significantly higher baseline and 48 h CEC, vWf, IL-6,TF and deltaTF levels, compared to low TIMI risk score (mean 2.4) patients (all p<0.05). Multivariate Cox regression analysis adjusted for clinical variables and TIMI risk score expressed as either continuous or categorical variable identified baseline CECs and deltavWf levels (both p< or =0.01) as independent predictors of subsequent cardiac events at both 14 days and 30 days. TIMI risk score for UA/NSTEMI identifies those patients with more profound vascular insult, inflammation and thrombogenicity that, in the 'high risk' patient group, predicts short-term outcomes, although vascular damage was the more sensitive predictor. These indices may further refine global risk stratification for short-term adverse cardiac events in these patients.

The effect of low social support on short-term prognosis in patients following a first myocardial infarction.

The objectives of the current study were (1) to assess adjustment in patients following a first myocardial infarction (MI) at 9 months compared with 4-6 weeks post-MI, (2) to examine the availability of and satisfaction with social support over time, and (3) to determine separate baseline psychosocial predictors of recurrent cardiac events. A questionnaire assessing post-traumatic stress disorder, anxiety, depression, health complaints, and social support, was distributed to consecutive patients 4-6 weeks and 9 months post-MI. Prior to assessment at follow-up, 8 (7%) of 112 patients had dropped out, and two had died due to cardiac causes. Objective clinical measures were obtained from medical records. There was an improvement in somatic and cognitive symptoms at follow-up, but no change in symptoms of arousal, depression, and anxiety. Half of the patients were afraid of a recurrent MI. There was a significant decrease in social support between baseline and follow-up, and lower social support at baseline was associated with a 10% increased risk of recurrent cardiac events at follow-up (OR: 0.90; 95% CI: 0.84 to 0.97) adjusting for all other variables. Some patients still experienced difficulties with psychosocial adjustment 9 months post-MI despite a reduction in somatic and cognitive symptoms. Social support decreased over time, which may have serious prognostic implications; lower social support at baseline was an independent predictor of recurrent events at 9 months. An important step for future research will be to investigate how social support can be enhanced in patients at risk.

Posttraumatic stress disorder in first-time myocardial infarction patients

Objectives The objectives of this study were to investigate the prevalence of posttraumatic stress disorder in patients with a first myocardial infarction compared with a random sample of healthy controls and to determine variables associated with the disorder. Design A questionnaire was distributed to 112 consecutive patients 4 to 6 weeks after infarction and to 115 healthy controls selected randomly from the general population. Objective clinical measures were obtained from the patients' medical records. Results Twenty-five (22%) patients qualified for a diagnosis of posttraumatic stress disorder (PTSD) compared with 8 (7%) controls with patients being more than a three-fold (OR: 3.84; 95% CI: 1.65 to 8.94) risk of having the disorder. When adjusting for other variables, the risk was reduced to above a two-fold risk (OR: 2.71; 95% CI: 0.99-7.41). In patients and controls, depression and neuroticism were associated with a diagnosis of PTSD adjusting for other variables. In patients, anxiety was associated with a diagnosis of PTSD adjusting for other variables. Left ventricular ejection fraction and symptoms of angina pectoris were not related to a diagnosis of PTSD in the patient group. Conclusions Given that previous research has shown that persons with PTSD are at increased risk of cardiovascular diseases, cardiac patients with the disorder may be at a higher risk of recurrent cardiac events. Although longitudinal studies are needed to confirm such a relationship, this disorder should not be overlooked because of its potential role in reinfarctions and mortality.

Soluble CD40L: risk prediction after acute coronary syndromes.

Elevated plasma concentrations of soluble CD40 ligand (sCD40L) indicate increased risk for future cardiovascular events in apparently healthy women. This study tested the hypothesis that plasma sCD40L, alone or in combination with troponin (cTnI) or C-reactive protein (CRP), may identify patients with acute coronary syndromes at heightened risk for recurrent cardiac events. In a nested case-control study (cases, n=195; controls, n=195) within the OPUS-TIMI16 trial, patients with the prespecified study end points death, myocardial infarction (MI), or congestive heart failure (CHF) within 10 months had significantly higher median (25th, 75th percentiles) sCD40L plasma levels than did controls (0.78 [0.34, 1.73] ng/mL versus 0.52 [0.16, 1.42] ng/mL, P<0.002). After adjustment for other risk predictors and levels of cTnI and CRP, sCD40L levels above median were associated with higher risk for death, MI, and the composite death/MI or death/MI/CHF (adjusted hazard ratios, 1.9 [P<0.05], 1.9 [P<0.001], 1.9 [P<0.001], and 1.8 [P<0.01], respectively). Interestingly, patients with elevated plasma levels of sCD40L and cTnI showed a markedly increased risk of death, MI, or death/MI/CHF compared with patients with the lowest levels of both markers (adjusted hazard ratios, 12.1, 7.2, and 4.3, respectively; all P<0.01). Elevated plasma levels of sCD40L identify patients with acute coronary syndromes at heightened risk of death and recurrent MI independent of other predictive variables, including cTnI and CRP. Notably, combined assessment of sCD40L with cTnI complements prognostic information for death and MI.

History of Hypertension and Enhanced Thrombogenic Activity in Postinfarction Patients

Hypertension is a risk factor for coronary thrombosis and death in cardiac patients mediated in part by endothelial damage or dysfunction and increased thrombogenicity. However, there are no data regarding the association between hypertension and thrombogenic activity in stable patients after myocardial infarction and limited data about the prognostic significance of thrombogenic factors in hypertensive patients after infarction. Therefore, levels of thrombogenic, lipid, and inflammatory factors were measured 2 months after an acute myocardial infarction in 461 hypertensive and 582 nonhypertensive patients. Thrombogenic factors included d-dimer, fibrinogen, plasminogen activator inhibitor-1, von Willebrand factor, factor VII, and factor VIIa. Lipid variables included cholesterol (total, HDL, LDL), triglyceride, lipoprotein (a), apolipoprotein-A1, and apolipoprotein-B. The prognostic significance of these factors for predicting cardiac events during a 2-year follow-up was evaluated in hypertensive and nonhypertensive patients. In comparison with nonhypertensive patients, those with hypertension had higher levels of d-dimer (607 versus 453 mg/L, P<0.001), fibrinogen (3.64 versus 3.43 g/L, P<0.001), plasminogen activator inhibitor-1 (29.7 versus 27.3 ng/mL, P=0.01), von Willebrand factor (159 versus 141 IU/dL; P<0.001), and higher levels of inflammatory markers (hsCRP and SAA). In multivariate analysis after adjustment for clinical covariates, elevated d-dimer was the only factor independently associated with a history of hypertension (OR, 1.38, P=0.05). d-Dimer was associated with an increased risk of recurrent cardiac events in both hypertensive (hazard ratio=3.02, P=0.005) and nonhypertensive (hazard ratio=2.42, P=0.02) patients. Thus, patients after infarction with a history of hypertension have enhanced thrombogenic activity, which predisposes them to recurrent cardiac events.

High-sensitivity C-reactive protein and cardiovascular risk in patients with coronary heart disease.

High-sensitivity C-reactive protein levels have received widespread attention because of a multitude of prospective studies that have shown that high levels of high-sensitivity C-reactive protein identify increased risk of initial cardiovascular events in coronary heart disease patients and increased risk of recurrent cardiac events in patients with stable and unstable angina, patients with acute myocardial infarction, and patients undergoing elective coronary revascularization procedures. In contrast to several other inflammatory markers, high-sensitivity C-reactive protein measurements are standardized and reproducible. The clinical significance of a reliable inflammatory marker includes identification of high-risk individuals, a gauge to monitor the activity of the disease, and a potential therapeutic target to alter the inflammatory component of the disease process. This review focuses on the importance of high-sensitivity C-reactive protein in cardiovascular risk stratification in coronary heart disease patients and discusses several preventive therapies that may reduce cardiovascular risk through reduction in high-sensitivity C-reactive protein.

Con: Postmenopausal hormone replacement therapy does not improve outcome in women undergoing coronary artery bypass graft surgery

CARDIOVASCULAR DISEASE is the leading cause of death in the United States in men and women. Deaths from cardiovascular disease outnumber deaths from all cancers combined and include approximately 500,000 women each year.1 The prognosis for women with coronary heart disease is worse than that for men, with higher mortality for women hospitalized for acute myocardial infarction, angioplasty, and coronary artery bypass graft surgery2-4 (CABG). Although the long-term survival for men and women discharged alive after CABG surgery is similar, the incidence of graft patency and survival free of angina is lower in women than in men.5 Despite the alarming prevalence of coronary heart disease in women, the incidence of coronary artery disease is still higher in men, with women developing atherosclerotic heart disease an average of 10 years later than men.6 This apparent female advantage is thought to be due to the protective effects of estrogen in women before menopause. In the Framingham study,7 researchers showed that the incidence of cardiovascular disease was 40 times higher in women aged 75 to 84 years compared with women aged 35 to 44 years. This ratio was not seen in men and likely reflects the relatively lower incidence of coronary artery disease in premenopausal women. Many observational studies have shown a lower risk of coronary heart disease in women who are taking postmenopausal hormone replacement therapy (HRT) when compared with women who are not, providing evidence to support the influential benefit of estrogen on risk for coronary heart disease. Estrogen raises high-density lipoprotein levels and lowers levels of low-density lipoproteins.8 These changes in lipoprotein profiles account for only 25% to 50% of the reduction in cardiovascular risk, however. Studies have shown evidence for estrogen-related endothelial-dependent vasodilation,9 antioxidant effects,10 and potential influences on coagulation.11 Given this information, it may be postulated that HRT would decrease the risk for recurrent cardiac events in women who have a history of coronary artery disease, resulting in improved clinical outcome. The authors conclusively show evidence against HRT in women with coronary artery disease, however, and illustrate that there is a paucity of data to confirm that this HRT improves outcome after CABG surgery.

Anticardiolipin antibodies and recurrent coronary events: a prospective study of 1150 patients. Thrombogenic Factors, and Recurrent Coronary Events Investigators.

The association of anticardiolipin (aCL) antibodies with coronary artery disease has been shown in several studies but remains controversial. We evaluated the association of aCL and anti-beta(2)-glycoprotein I (abeta(2)GPI) antibodies with the risk of recurrent cardiac events in postinfarction patients. The study population consisted of 1150 patients with acute myocardial infarction. Levels of IgG and IgM aCL and abeta(2)GPI antibodies were determined on sera collected before hospital discharge. There were 131 recurrent cardiac events (nonfatal myocardial infarctions or cardiac deaths) over a mean follow-up period of 24.6 months. Patients with elevated IgG aCL antibodies had a higher event rate than patients with low levels (P:=0.05). Multivariate Cox analysis after adjustment for relevant clinical covariates showed that elevated levels of IgG aCL (hazard ratio=1. 63; P:=0.01) and low levels of IgM aCL (hazard ratio of 1.76; P:=0. 02) antibodies contribute independent risks for recurrent cardiac events. Patients with elevated IgG aCL and low IgM aCL antibody levels had a 3-fold higher risk of recurrent cardiac events than patients with low IgG aCL and elevated IgM aCL antibody levels (P:<0. 001). There was no significant association of the abeta(2)GPI antibodies with recurrent cardiac events. In postinfarction patients, elevated IgG aCL and low IgM aCL antibodies are independent risk factors for recurrent cardiac events. Patients with both elevated IgG aCL and low IgM aCL antibodies have the highest risk. These findings shed additional light on the mechanistic role of aCL antibodies in coronary artery disease in patients without autoimmune diseases.

Gender-related differences in thrombogenic factors predicting recurrent cardiac events in patients after acute myocardial infarction

Thrombosis contributes to recurrent coronary events in patients after acute myocardial infarction (AMI), but prognostic significance of thrombogenic factors by gender is unknown. This study aimed to determine gender-related differences in the prognostic significance of thrombogenic factors for predicting cardiac events (nonfatal reinfarction or cardiac death) in postinfarction patients. Blood levels of the following factors were measured 2 months after AMI in 791 men and 254 women: fibrinogen, von Willebrand factor, factor VII and VIIa, plasminogen activator inhibitor, D-dimer, cholesterol, apolipoprotein A-1, apolipoprotein B, lipoprotein(a), triglycerides, and high-density lipoprotein cholesterol. After adjustment for clinical covariates, levels of apolipoprotein A, high-density lipoprotein cholesterol, fibrinogen, and factor VIIa were significantly higher in postinfarction women than men. During a mean 26-month follow-up, there were 67 cardiac events (8.5%) in men and 14 (5.5%) in women (p = 0.11). In the multivariate Cox model, elevated levels of factor VIIa were a significant predictor of cardiac events in women (p = 0.022) but not in men (p = 0.80), with significant gender-related effect (hazard ratio 2.80 vs 0.92, respectively; p <0.05). D-dimer had prognostic value in men (p = 0.006) but not in women (p = 0.36), although the difference between hazard ratios for men and women was not significant (2.35 vs 1.58, respectively; p = 0.49). In conclusion, elevated levels of factor VIIa are associated with an increased risk of recurrent cardiac events in postinfarction women, but not in men. D-dimer is more predictive for cardiac events in postinfarction men than women. These observations indicate possible gender-related differences in the pathophysiologic mechanisms of recurrent cardiac events.

Enhancing Recovery in Coronary Heart Disease Patients (ENRICHD): Study design and methods

Psychosocial factors, particularly depression and lack of social support, are important predictors of morbidity and mortality in patients with coronary heart disease. This article describes the design and methods of the Enhancing Recovery in Coronary Heart Disease Patients (ENRICHD) study, a multicenter, randomized clinical trial involving 3000 patients enrolled after acute myocardial infarction. ENRICHD aims to investigate the effects of a psychosocial intervention that targets depression and/or low social support on survival and reinfarction among adult men and women who are at high risk for recurrent cardiac events because of psychosocial factors (depressive or social isolation). Design features include the use of an individually tailored yet standardized intervention, rigorous clinical trial methods, and enrollment of a large number of women and minorities. (Am Heart J 2000;139:1-9.)

Evidence supporting secondary prevention strategies.

Currently 14 million individuals in the United States have coronary disease. Within the next 2 decades, this number is expected to increase to 21 million persons. To minimize the excessive risk of recurrent cardiac events in these people, evidence-based, cost-effective prevention strategies must be developed. This review highlights the evidence supporting commonly used means of secondary prevention and is divided into two major sections: lifestyle modifications and pharmacologic interventions. Lifestyle changes discussed include smoking cessation, especially newer pharmacologic adjuncts; the efficacy of dietary interventions; and current inroads into the treatment of depression in recurrent events. Pharmacologic innovations include reexamination of a role for warfarin; continued advances in the treatment of hyper- and dyslipidemias, new roles for beta-blockade in congestive heart failure, and finally a view of future measures, risk and targets of risk intervention.

Rehabilitation of cardiac patients in the twenty-first century: Changing paradigms and perceptions

Rehabilitation of the coronary patient has changed dramatically over the past 40 years. The deleterious effects of prolonged bed rest have prompted the liberalization of activity soon after an acute cardiac event. Exercise-based cardiac rehabilitation has been shown to provide a 20–24% reduction in total and cardiovascular-related mortality. Adjunctive upper body aerobic exercise and mild to moderate resistance training can improve muscular strength and endurance in clinically stable coronary patients and attenuate the cardiovascular demands of occupational and leisure-time activities. Risk stratification has emerged as the centrepiece of strategies aimed at stabilizing or enhancing the clinical status of post-myocardial infarction patients, as well as vocational counselling. Moreover, randomized controlled trials have confirmed the hypothesis that lipid lowering is associated with, and possibly preceded by, plaque stabilization and a reduction in the risk of recurrent cardiac events.

Significance of location (anterior versus inferior) and type (Q-wave versus non-Q-wave) of acute myocardial infarction in patients undergoing percutaneous transluminal coronary angioplasty for postinfarction ischemia

Predictors of increased risk for recurrent cardiac events and death after acute myocardial infarction include postinfarction myocardial ischemia, anterior location of the infarct, and non-Q-wave versus Q-wave infarction. Although coronary angioplasty is performed in patients with postinfarction ischemia to alleviate symptoms, the outcome according to location and type of infarction and the effect on prevention of subsequent myocardial infarction and death are not known. To determine if location and type of myocardial infarction provide prognostic information in patients with postinfarction ischemia, we analyzed morbidity and mortality during and after coronary angioplasty according to the location (anterior vs inferior) and type (Q-wave vs non-Q-wave) of myocardial infarction in 505 consecutive patients. The incidence of recurrent angina, repeat coronary angioplasty, coronary bypass surgery, reinfarction, and death during long-term follow-up after hospital discharge (mean 34 ± 19 months) for the 440 patients with an initial successful angioplasty was also compared. During the procedure, there was no difference in the primary success rate or mortality among the different groups; however, more patients with anterior non-Q-wave myocardial infarction underwent emergent bypass grafting after unsuccessful coronary angioplasty (p = 0.001). Multivariate Cox proportional-hazards analyses controlling for age, gender, number of diseased vessels, location, type of infarction, and year of coronary angioplasty revealed that more patients with anterior infarction had ≥1 cardiac event (repeat angioplasty, coronary artery bypass grafting, reinfarction, or death) than did those with inferior infarction (RR 1.80, 95% confidence interval [CI] 1.22 to 2.65, p = 0.003). The rate of reinfarction or death was 1.93 times higher in patients with anterior than inferior infarction (95% CI 0.97 to 3.82, p = 0.057). There was no difference in these cardiac events for Q-wave versus non-Q-wave infarction (RR 1.15, 95% CI 0.78 to 1.69, p = 0.47). These results suggest that anterior location, but not type, of infarction was associated with a greater likelihood of a cardiac event at follow-up.

Association between silent myocardial ischemia and prognosis: Insensitivity of angina pectoris as a marker of coronary artery disease activity

The clinical syndrome of angina pectoris was accurately described over 200 years ago by Sir William Heberden. However, in recent years, we have learned that many episodes of myocardial ischemia occur that are not accompanied by symptoms of angina pectoris. These silent ischemic episodes may be detected either during exercise testing, using electrocardiographic criteria that can be combined with scintigraphic studies evaluating myocardial blood flow (thallium perfusion studies) or left ventricular function (gated blood pool scans). In addition, continuous electrocardiographic (Holter) monitoring can be used for the detection of transient ST-segment changes; these changes on Holter monitoring have been correlated with abnormalities of myocardial perfusion and function, indicating that they represent true ischemic events. Studies have shown that patients with coronary artery disease who have evidence of ongoing ischemia, whether symptomatic or silent, have an increased risk for experiencing subsequent cardiac events than patients without evidence of ischemia. Many studies have demonstrated that ischemia during an exercise study after myocardial infarction identifies patients at high risk for recurrent cardiac events, whether or not the ischemia is associated with angina pectoris. Holter monitoring has allowed for the detection of ischemic events out of hospital in ambulatory patients. Studies in stable angina patients have shown that there are many asymptomatic episodes in this setting, which are often occurring at low heart rates during activities of everyday life, without an apparent significant increase in myocardial oxygen demands, and these episodes may even be precipitated by mental stress. Several studies have suggested that the presence of ongoing silent ischemia in unstable angina patients and postinfarction patients can identify those at higher risk for cardiac events. The results of these studies will be discussed. The treatment of coronary artery disease has been for the most part symptomatic, with the primary goal of relieving symptoms of angina pectoris. Several exceptions include patients with left main disease or severe proximal 3-vessel disease, who have extensive amounts of myocardium at risk and who are generally referred for bypass surgery. These new data indicating that the presence and severity of asymptomatic ischemia have adverse prognostic implications suggest that therapy should be directed at reducing the total ischemic profile, i.e., symptomatic and asymptomatic episodes. Guidelines for appropriate screening and therapeutic strategies will be discussed.

A prospective clinical, scintigraphic, angiographic and functional evaluation of patients after inferior myocardial infarction with and without right ventricular dysfunction

To elucidate the functional and prognostic significance of right ventricular dysfunction after acute inferior wall myocardial infarction, 74 consecutive patients with inferior infarction were prospectively evaluated with gated equilibrium blood pool imaging at rest, submaximal exercise thallium-201 scintigraphy and coronary angiography before hospital discharge. In addition, symptom-limited stress thallium-201 scintigraphy was performed in 61 patients at 3 months, and all patients were followed up clinically for 23 +/- 15 months. Utilizing predetermined radionuclide angiographic criteria, 47 patients (Group I) had normal right ventricular function, 12 patients (Group II) had mild to moderate dysfunction and 15 patients (Group III) had severe right ventricular dysfunction. There were no significant differences among the groups with regard to age, history of prior myocardial infarction, peak creatine kinase values, maximal Killip functional class, number or type of in-hospital complications, left ventricular ejection fraction, prevalence of multivessel disease or the distribution and severity of disease affecting the infarct-related vessel. Exercise tolerance as assessed by treadmill time, blood pressure-heart rate product and peak work load in METS was comparable among the three groups, both before hospital discharge and at 3 month follow-up. No differences in indicators of exercise-induced ischemia were noted among the groups, including the prevalence of redistribution thallium-201 defects, ST segment depression or symptoms of chest pain. Finally, cardiac mortality, reinfarction rate and the incidence of medically refractory angina pectoris were similar in the three groups. Thus, right ventricular dysfunction after acute inferior wall myocardial infarction does not appear to limit exercise tolerance or identify a subgroup of patients at higher risk for recurrent cardiac events.

Exercise stress testing in the post-myocardial infarction patient

Recent studies indicate that predischarge evaluation of the post-myocardial infarction (MI) patient is important in predicting their subsequent course and the need for specific treatment. Left ventricular function, residual ischemia and the tendency toward ventricular arrhythmias can all be assessed noninvasively in the late hospital phase. Stress testing is 1 of the most useful and widely available of these techniques. An impaired hemodynamic response to exercise expressed by excessive tachycardia, plateau or falling blood pressure or reduced work load capacity suggests an increased risk of recurrent cardiac events in the near future. Angina or electrocardiographic abnormalities, including arrhythmias, also indicate a less favorable outcome. A good performance in a post-MI stress test is associated with a relatively good prognosis. The exercise electrocardiogram, therefore, appears to be a useful screening device for evaluating post-MI patients. Other noninvasive tests such as radionuclide ventriculography, exercise thallium scanning, Holter monitoring and echocardiography greatly augment the predictive value of exercise electrocardiography, and a patient profile should be developed using all the available clinical and laboratory data. Patients with a poor prognostic profile may then undergo further testing, such as coronary angiography, and their subsequent therapy modified appropriately.