Cardiovascular disorders and exposure to chemical pollutants

Introduction

Exposure with some chemical can cause cardiovascular disorders. Occupational exposures with chemicals are modifiable risk factors for cardiovascular diseases. The Objective of this study was the determination of cardiovascular disorders in industries with occupational exposures.

Materials and methods

Study was a cross-sectional method and was done on workers of related industries. The study was done with a physical examination and checklist by getting health and illness history and clinical tests about the risk factors and cardiovascular disorders. According to exposures the population of the study was divided into 3 groups. Data were analyzed with SPSS 16, by considering p < 0.05 as significant.

Results

The frequency of unstable angina and stable angina were the most in group 1. The relative risk for unstable angina was 1.55 (1.46-1.61) in group 1 and for stable angina was 1.54 (1.47-1.62) in this group. The risk of thrombophlebitis was 8.48 (7.07-10.17) in group 2.

Conclusions

Workers in industry with chemical pollutants had cardiovascular disorders. The occupational exposures, especially chemical agents are effective on cardiovascular system.

Comparative cardiovascular safety of LABA/LAMA FDC versus LABA/ICS FDC in patients with chronic obstructive pulmonary disease: a population-based cohort study with a target trial emulation framework

BACKGROUND

Use of combinations of long-acting β2 agonists/long-acting muscarinic antagonists (LABA/LAMA) in patients with chronic obstructive pulmonary disease (COPD) is increasing. Nevertheless, existing evidence on cardiovascular risk associated with LABA/LAMA versus another dual combination, LABA/inhaled corticosteroids (ICS), was limited and discrepant.

AIM

The present cohort study aimed to examine comparative cardiovascular safety of LABA/LAMA and LABA/ICS with a target trial emulation framework, focusing on dual fixed-dose combination (FDC) therapies.

METHODS

We identified patients with COPD who initiated LABA/LAMA FDC or LABA/ICS FDC from a nationwide Taiwanese database during 2017-2020. The outcome of interest was a hospitalized composite cardiovascular events of acute myocardial infarction, unstable angina, heart failure, cardiac dysrhythmia, and ischemic stroke. Cox regression models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for composite and individual cardiovascular events after matching up to five LABA/LAMA FDC initiators to one LABA/ICS FDC initiator using propensity scores (PS).

RESULTS

Among 75,926 PS-matched patients, use of LABA/LAMA FDC did not show a higher cardiovascular risk compared to use of LABA/ICS FDC, with a HR of 0.89 (95% CI, 0.78-1.01) for the composite events, 0.80 (95% CI, 0.61-1.05) for acute myocardial infarction, 1.48 (95% CI, 0.68-3.25) for unstable angina, 1.00 (95% CI, 0.80-1.24) for congestive heart failure, 0.62 (95% CI, 0.37-1.05) for cardiac dysrhythmia, and 0.82 (95% CI, 0.66-1.02) for ischemic stroke. The results did not vary substantially in several pre-specified sensitivity and subgroup analyses.

CONCLUSION

Our findings provide important reassurance about comparative cardiovascular safety of LABA/LAMA FDC treatment among patients with COPD.

Comparison of ticagrelor and clopidogrel on platelet function and prognosis in unstable angina

PURPOSE

This study aims to compare the effects of ticagrelor and clopidogrel on platelet function, cardiovascular prognosis, and bleeding in patients with unstable angina pectoris.

METHODS

Patients with unstable angina pectoris undergoing percutaneous coronary intervention (PCI) were enrolled (January 2018-December 2019). In total, 212 patients were treated with ticagrelor (90 mg twice daily) and 210 patients were treated with clopidogrel (75 mg once daily). Thromboelastography and light transmission aggregometry were used to measure the platelet aggregation rate (PAR). High-sensitivity troponin T (hs-TnT), pro-brain natriuretic peptide (NT-proBNP), high-sensitivity C-reactive protein (CRP), and heart-type fatty acid-binding protein (h-FABP) were measured to assess myocardial injury after PCI. Cardiovascular prognosis and bleeding events were evaluated in hospital and 12 months after discharge.

RESULTS

The PAR was significantly slower with ticagrelor (P < 0.001). hs-TnT, NT-proBNP, CRP, and h-FABP increased after compared with before PCI in both groups (P < 0.05). hs-TnT (P < 0.001) and h-FABP (P < 0.001) increased more significantly with clopidogrel. The in-hospital and 12-month major adverse cardiovascular event (MACE) rates were not significantly different between the two groups. The in-hospital total bleeding event rate was higher with ticagrelor (P < 0.05). Minor bleeding and total bleeding were more frequent at the 12-month follow-up in the ticagrelor group (P < 0.05).

CONCLUSION

Ticagrelor was more effective in suppressing the PAR than clopidogrel and reduced PCI-induced myocardial injury in patients with unstable angina pectoris. However, it increased in-hospital and 12-month bleeding events and had no benefit on in-hospital and 12-month MACEs.

Unstable Angina: A Serious Adverse Event following Gemcitabine-Cisplatin Based Chemotherapy

A 29 year male, with an inoperable adenocarcinoma of gall bladder was initiated on gemcitabine and a platinum compound based chemotherapy. During 4th cycle of chemotherapy, patient complained of chest pain following cisplatin and gemcitabine infusion. ECG was suggestive of acute coronary syndrome, which was successfully managed by antianginal therapy. Fifth cycle of chemotherapy was uneventful. Patient died of cardiovascular collapse before receiving the 6th cycle of chemotherapy. As per Naranjo adverse drug reaction probability scale, causal association of the event with cisplatin and gemcitabine was probable and possible respectively. It is advised to routinely assess the cardiovascular status of patients before and during cisplatin and/or gemcitabine based chemotherapy.

A Destabilized Case of Stable Effort Angina Pectoris Induced by Low-dose Adenosine Triphosphate

A 79-year-old man was diagnosed with sudden deafness. He had previously experienced a suspected episode of angina pectoris. At a local hospital, after 500 mg of hydrocortisone and 80 mg adenosine triphosphate (ATP) were administered, he became aware of chest discomfort. An electrocardiogram revealed serious ST-segment depressions. He was diagnosed with a non-ST elevated myocardial infarction (NSTEMI). Emergency coronary angiography revealed triple vessel disease, and the lesion was successfully stented. The mechanisms whereby the stable effort angina pectoris destabilized in this case were thought to include a reduction of the local blood flow because of an ATP product and probable thrombus formation in response to the administered steroids.

Long term exposure to ambient air pollution and incidence of acute coronary events: prospective cohort study and meta-analysis in 11 European cohorts from the ESCAPE Project

OBJECTIVES

To study the effect of long term exposure to airborne pollutants on the incidence of acute coronary events in 11 cohorts participating in the European Study of Cohorts for Air Pollution Effects (ESCAPE).

DESIGN

Prospective cohort studies and meta-analysis of the results.

SETTING

Cohorts in Finland, Sweden, Denmark, Germany, and Italy.

PARTICIPANTS

100 166 people were enrolled from 1997 to 2007 and followed for an average of 11.5 years. Participants were free from previous coronary events at baseline.

MAIN OUTCOME MEASURES

Modelled concentrations of particulate matter <2.5 μm (PM2.5), 2.5-10 μm (PMcoarse), and <10 μm (PM10) in aerodynamic diameter, soot (PM2.5 absorbance), nitrogen oxides, and traffic exposure at the home address based on measurements of air pollution conducted in 2008-12. Cohort specific hazard ratios for incidence of acute coronary events (myocardial infarction and unstable angina) per fixed increments of the pollutants with adjustment for sociodemographic and lifestyle risk factors, and pooled random effects meta-analytic hazard ratios.

RESULTS

5157 participants experienced incident events. A 5 μg/m(3) increase in estimated annual mean PM2.5 was associated with a 13% increased risk of coronary events (hazard ratio 1.13, 95% confidence interval 0.98 to 1.30), and a 10 μg/m(3) increase in estimated annual mean PM10 was associated with a 12% increased risk of coronary events (1.12, 1.01 to 1.25) with no evidence of heterogeneity between cohorts. Positive associations were detected below the current annual European limit value of 25 μg/m(3) for PM2.5 (1.18, 1.01 to 1.39, for 5 μg/m(3) increase in PM2.5) and below 40 μg/m(3) for PM10 (1.12, 1.00 to 1.27, for 10 μg/m(3) increase in PM10). Positive but non-significant associations were found with other pollutants.

CONCLUSIONS

Long term exposure to particulate matter is associated with incidence of coronary events, and this association persists at levels of exposure below the current European limit values.

[Two cases of unstable angina in patients treated with bevacizumab]

Adverse events associated with bevacizumab (BV) were haemorrhage, impaired wound healing and arterial thromboembolism. We report 2 patients with colorectal cancer who underwent percutaneous coronary intervention (PCI) for unstable angina soon after administration of chemotherapy including BV. CASE 1: A 74-year-old male with rectal cancer and simultaneous liver metastases was admitted to our hospital for unstable angina. Before admission he had received 4 courses of chemotherapy including BV. He had no coronary risk factors besides old age. Since coronary angiography (CAG) revealed significant stenosis in the mid-left circumflex coronary artery, PCI with a coronary stent was performed without any complications. CASE 2: A 67-year-old male with colon cancer and liver and lung metastases was referred to our Dept. of Internal Medicine for unstable angina. Before referral, he had undergone 28 courses of chemotherapy including BV. He had a history of familial hyperlipidemia and smoking. Since CAG revealed significant stenoses in the proximal left anterior descending coronary artery, PCI with coronary stents was performed without any complications. These 2 patients had no angina after PCI. PCI with coronary stent was safely performed in this patient with unstable angina soon after administration of chemotherapy including BV.

Adjusted indirect comparison of celecoxib versus rofecoxib on cardiovascular risk

To compare the magnitude of celecoxib versus rofecoxib on the cardiovascular risk. We performed adjusted indirect comparison of celecoxib versus rofecoxib for cardiovascular events using two data on The Adenomatous Polyp Prevention on Vioxx (APPROVe) trial and Adenoma Prevention with Celecoxib (APC) trial. Baseline characteristics of the patients and placebos were comparable in both trials, in terms of age, sex, hypertension, diabetes mellitus, smoking, and hypercholesterolemia. The overall incidence of cardiovascular events was similar in both groups (rofecoxib 48/1,287 versus celecoxib 48/1,356, p = 0.79). The relative risks (RRs) of all myocardial infarction or sudden death from cardiac causes were increased in both rofecoxib and celecoxib groups [rofecoxib versus placebo; RR 1.35, 95% confidence interval (CI) 1.07-1.69, p = 0.03, celecoxib versus placebo; RR 1.35, 95% CI 1.14-1.51, p = 0.01]. The RRs for cardiovascular events derived from the adjusted indirect comparisons of the two coxibs did not significantly differ from unity (celecoxib versus rofecoxib; RR 0.95, 95% CI 0.76-1.19, p = 0.67). The adjusted indirect comparison analysis shows that celecoxib and rofecoxib may have similarly effect of cardiovascular events when used for 3 years.

Macrolide use and the risk of vascular disease in HIV-infected men in the Multicenter AIDS Cohort Study

Background: There has been increasing concern that HIV-infected individuals may be more at risk for cardiovascular events in the highly-active antiretroviral therapy (HAART) era. This study examined the risk of thromboembolic events in HIV-infected and non-infected individuals and the effect of macrolide prophylaxis on those outcomes. Methods: A subcohort analysis was undertaken using data collected in the Multicenter AIDS Cohort Study to examine the relative risk of vascular events (myocardial infarction, unstable angina and ischaemic stroke). Cox proportional hazard model using age as the time scale with time varying cofactors obtained at each semi-annual visit were used to assess the independent effect of macrolide use. Results: Controlling for other significant effects including race and smoking, HIV-infection was not independently associated with vascular events. Increased risk was observed among those who used HAART (relative hazard 1.09, 95% confidence intervals 1.00–1.19 in multivariate model), antihypertensive treatment (1.81 [1.26–2.60]), lipid-lowering medication (1.65 [1.12–2.42]), and antibiotics (1.72 [1.25–2.36]). The protective association of macrolide use for a vascular event in the HAART era was also significant (0.10 [0.01–0.75]). Conclusions: Traditional risk factors are important in the pathogenesis of vascular events in HIV-infected individuals. Macrolide antibiotics may have a protective effect in the HIV-infected individuals in the HAART era.

[Clinical presentation of ST-elevation acute coronary syndrome in the course of intoxication with megadose of rifampicin. A case report]

We present a case of 29-year-old male, with coronary artery disease in mother's history, after suicidal poisoning with 30 g of rifampicin, who presented severe chest pain, ST elevations in ECG, low values of blood pressure and elevated troponin I. Echocardiography revealed generalised hypokinesia, and depressed contractility--left ventricle ejection fraction was 7%. Urgent coronary angiography has shown normal epicardial arteries with slow contrast inflow. The toxic properties of rifampicin as well as hypotension due to dehydration are considered reasons of symptoms in the presented case.

Acute coronary syndrome induced by oral capecitabine

A 41-year-old woman who was undergoing oral chemotherapy with capecitabine for metastatic breast cancer presented with recurrent episodes of chest pain associated with electrocardiographic signs of diffuse ST segment elevation. After spontaneous pain relief, the electrocardiogram showed ischemic evolution in the anterior precordial leads. Coronary and ventricular angiography, performed 24 h later, showed normal coronary arteries and normal left ventricular function. After therapy with capecitabine was discontinued, the patient did not experience further episodes of chest pain. After a nine-month follow-up, she remains alive, with a good performance status and without clinical evidence of persistent ischemia.

Myocardial damage after inhalation of chloramines

The objective of this case report was to document a rare case of myocardial damage, in the context of an accidental inhalation of chloramines, demonstrated by electrocardiogram and myocardium-specific enzymes.

[Acute coronary syndrome after diclofenac induced coronary spasm]

We report about a 67-year old man, who was submitted to our clinic with acute coronary syndrome. The cardiac catheterization showed a proximal thrombus in the left anterior descending (LAD). The other coronary arteries did not have significant lesions. After percutaneous transluminal coronary angioplasty with stent-implantation into the proximal LAD the patient remained clinically stable. Cardiac enzymes confirmed no myocardial necrosis. Three days after the acute coronary syndrome the patient developed a podagra, which was treated with colchicinum, diclofenac and local cooling. Five hours after initial therapy the patient developed severe symptoms of angina pectoris and electrocardiographical signs of an acute posterior and anterior myocardial infarction. Immediate coronary angiography demonstrated extended vasospasm of the right coronary artery. Intracoronary application of verapamil and nitroglycerin resolved the coronary spasm. The patient reported about a self-indicated application of diclofenac six hours before hospital admission. This case demonstrates that oral application of diclofenac can provoke coronary vasospasm.

Determinants of ELISA D-dimer sensitivity for unstable angina pectoris as defined by coronary catheterization

Unstable angina pectoris is associated with elevated D-dimer levels. However, the operating characteristics (sensitivity, specificity, positive and negative predictive value) of the D-dimer assay for the diagnosis of coronary artery disease (CAD) are unknown. Using a prospective, observational design, we collected blood from 54 patients with unstable angina pectoris at admission and assayed for ELISA D-dimer levels. The sensitivity, specificity, and negative and positive prediction values for angiographically determined coronary artery disease were calculated at multiple discriminate levels. All patients underwent coronary catheterization. A statistically significant correlation was noted between ELISA D-dimer levels and age, male sex, hypertension, use of beta-blocker, fibrinogen levels and catheterization findings. No correlation was noted between ELISA D-dimer levels and degree of the coronary artery disease. Best results were provided at a discriminate level of 270 ng/ml, with sensitivity 70%, negative predictive value 72%, and overall accuracy 67%. All discriminate levels, however, provided values too low for diagnosis. In conclusion, ELISA D-dimer assay is a non-sensitive, non-specific test for coronary artery disease as defined by coronary catheterization. However, the assay adds information regarding the severity of disease in patients presenting with acute coronary syndrome.

Acute coronary syndrome and crystal methamphetamine use: a case series

"Ice" is a form of methamphetamine commonly used as a recreational drug in Hawaii and the Philippines, but seldom encountered in the continental United States. It differs in appearance from methamphetamine tablets, but otherwise has exactly the same molecules, only arranged in a crystalline structure. A sizeable body of in vitro, animal, and autopsy data suggest a linkage between methamphetamine use and myocardial pathology. In this report, we describe a series of eight patients who developed unstable angina or acute myocardial infarction in association with smoking crystal methamphetamine. The findings, to a large extent, resemble those with cocaine-associated acute coronary syndromes. Given the widespread abuse of methamphetamine among young age groups, the recognition and primary prevention of cardiovascular toxic effects is of mounting socioeconomic importance.

[Angina related to 5-Fluorouracil]

Treatment with 5-fluorouracil is common in oncological patients. Side effects on bone marrow, skin, and mucous membranes have been reported. Cardiotoxicity, which is less predictable, can be life-threatening. Manifestations include angina, arrhythmias, infarction, heart failure and cardiogenic shock. The toxic mechanisms that might be involved have been much discussed but have not yet been clearly established. Current evidence supports the possibility of a metabolic effect in common with the cascade secondary to ischemia due to coronary disease. Based on a case report, we discuss the usual clinical presentation, treatment and prognosis. Finally we make recommendations for managing patients being treated with 5-fluorouracil.

Association between inhaled beta-agonists and the risk of unstable angina and myocardial infarction

BACKGROUND

beta-Adrenoceptor agonists (beta-agonists) are commonly used to treat obstructive lung diseases, and preliminary studies have suggested they are associated with an increased risk of adverse cardiovascular outcomes. We further examined the association between acute coronary syndromes and inhaled beta-agonist therapy.

METHODS

We performed a nested, case-control study using data that were collected as part of a larger, ongoing, prospective study of quality improvement in the primary care clinics of seven Veterans Administration Medical Centers. We identified 630 patients with unstable angina or acute myocardial infarction hospitalized between 1996 and 1999. We frequency matched these case patients to 10,486 control subjects according to clinic location, and randomly assigned each an "index date." The computerized pharmacy database at each center was used to ascertain beta-agonist use. Cardiovascular risk factors were assessed from mailed questionnaires and electronic medical records, which included inpatient and outpatient diagnoses, medications, and laboratory results.

RESULTS

In comparison with patients who had not filled a beta-agonist prescription during the 90 days prior to their index date, patients who had filled a beta-agonist prescription had an increased risk of experiencing an acute coronary syndrome. The increased risk of an acute coronary syndrome persisted after adjusting for age and cardiovascular risk factors, including hypertension, diabetes, and smoking history. Moreover, there was a dose-response relationship with an adjusted odds ratio (OR) of 1.38 for one to two metered-dose inhaler (MDI) canisters (95% confidence interval [CI], 0.86 to 2.23), an OR of 1.57 for three to five MDI canisters (95% CI, 1.01 to 2.46), and an OR of 1.93 for six or more MDI canisters (95% CI, 1.23 to 3.03). After stratifying for receipt of a beta-blocker prescription, the adjusted OR in subjects who did not receive a beta-blocker was 1.55 for one to two MDI canisters (95% CI, 0.60 to 3.99), an OR of 4.07 for three to five canisters (95% CI, 2.17 to 7.64), and an OR of 3.83 for six or more canisters (95% CI, 2.02 to 7.29). Subjects who had received both beta-blockers and beta-agonists had no increase in risk in acute coronary syndromes unless they had filled six or more beta-agonist MDI canisters.

CONCLUSIONS

A prescription for inhaled beta-agonists may increase the risk of myocardial infarction and unstable angina in patients with COPD.

[Emergency coronary angioplasty following treatment with 5-fluorouracil]

INTRODUCTION

The incidence of cardiac toxicity due to 5-fluorouracil (5-FU) ranges from 1.2 to 18%. Most complications occur at the time of the first cure. Their mechanisms have not yet been clearly defined.

EXEGESIS

The authors report a case of unstable angina induced by 5-FU. A coronary angioplasty was performed on a previously ignored coronary lesion.

CONCLUSION

Recent studies support the hypothesis that 5-FU has endothelial toxicity resulting in thrombogenic effect and release of vasoactive substances. Unstable angina pectoris would be related to plaque rupture caused by 5-FU. Patients with previous history of coronary disease are at significantly increased risk for 5-FU-induced cardiotoxicity. They probably would benefit from continuous electrocardiographic monitoring. Rechallenge with 5-FU after cardiotoxicity problems should include only those patients for whom there is no alternative treatment.

Unstable angina associated with sertraline

An 81-year-old woman reported with chest pain occurring shortly after initiating treatment with sertraline. She had no prior history of cardiovascular disease. She developed nausea and malaise 4 h after her first dose, which resulted in avoidance of further treatment. After voluntarily reinitiating sertraline 10 days later, she again developed nausea and malaise but persisted with treatment. On the second day, her gastrointestinal symptoms were accompanied by crushing retrosternal chest pain radiating to both arms and resolving spontaneously after 10 mins. Following the third dose of sertraline, the patient experienced severe and persistent crushing retrosternal chest pain radiating to both arms. She was hospitalized with a diagnosis of unstable angina and treated with acetylsalicylic acid, intravenous heparin and nitroglycerin. The temporal relationship of chest pain onset following ingestion of sertraline is strongly suggestive of an adverse medication effect.

Low dose aspirin in patients with ischemic heart disease may precipitate secondary myocardial infarction

We conducted a retrospective case-control study to compare the frequency of myocardial infarction (MI) or unstable angina (UA) precipitated by aspirin-induced upper gastrointestinal (GI) bleeding among patients with and without ischemic heart disease(IHD), and to determine whether the risk of MI or UA is related to the hemoglobin level on admission. Of the 51 patients admitted to the hospital between 1987 and 1994 because of aspirin-induced upper GI bleeding, 33 had ischemic heart disease. The prevalence of MI and UA inpatients with IHD and aspirin-induced upper GI bleeding was significantly higher than in patients without IHD (42% vs. 5.5% respectively) (P < 0.005). Of the patients with upper GI bleeding and a hemoglobin concentration of 5-8 g/dl, 75% had either MI or UA in comparison to 50% and 18% of the patients with hemoglobin concentrations of 8-10 and 10-14 g/dl respectively. We conclude that low dose aspirin therapy may precipitate MI or UA, especially in patients with IHD, by inducing upper GI bleeding. Patients with IHD who use low dose aspirin to prevent MI should be instructed how to identify emerging symptoms of peptic ulcer as well as the initial signs of upper GI bleeding. Early diagnosis and treatment of these patients might prevent the induction of secondary MI or UA.

Unstable angina and exposure to carbon monoxide

Inhalation of small amounts of carbon monoxide diminishes the pain threshold in patients with stable angina pectoris. The aim of this study was to identify and describe patients who had been exposed unknowingly to toxic inhalations of this gas and subsequently presented to hospital with a clinical picture of unstable angina. Blood carboxyhaemoglobin levels of 104 patients referred with unstable angina to a coronary care unit were determined on admission. The likely source of carbon monoxide was identified in all patients. Three patients had definite carbon monoxide intoxication. Another five patients had evidence of minor exposure. When the three cases with carbon monoxide poisoning were excluded, the mean carboxyhaemoglobin level was 2.5% (+/- 1.3) for smokers (n = 30) and 0.6% (+/- 0.5) for non-smokers (n = 71). Use of fossil fuel combustion in an enclosed environment was responsible for the three most serious intoxications and one of the minor cases. We suggest that a number of patients admitted for coronary care with unstable angina may have significant carbon monoxide poisoning. This intoxication is often overlooked by attending physicians with the result that high concentration oxygen therapy is not administered, when it is in fact a necessary part of treatment.

Pulmonary edema as a complication of interleukin-2 therapy

Eight patients underwent IV bolus therapy with recombinant interleukin-2 (Cetus Corporation, Emeryville, CA) for treatment of metastatic melanoma or renal cell carcinoma. The patients were randomized to receive interleukin-2 alone or interleukin-2 in combination with lymphokine-activated killer cells. Radiographs showed pulmonary edema in five of the eight patients. The changes ranged from mild interstitial edema (two patients) to frank pulmonary edema (three patients). The edema generally resolved within 4 days after the termination of therapy (four patients), however, one patient developed edema and arrhythmias approximately 7 days after interleukin-2 therapy ended. Seven of the eight patients had either cardiac arrythmias or angina. The mechanisms that contribute to the pathogenesis of these cardiac complications with interleukin-2 therapy remain unclear. The development of pulmonary edema is thought to be caused by capillary leakage and cardiac pulmonary edema due to cardiac toxicity of the drug. The radiologic appearances of these types of pulmonary edema were indistinguishable from one another and from other causes of pulmonary edema. Our study shows that interleukin-2 can cause pulmonary edema, cardiac arrhythmias, and unstable angina. The severity of these conditions is unrelated to dose.

Acute nifedipine withdrawal: consequences of preoperative and late cessation of therapy in patients with prior unstable angina

Reports of acute ischemic events after withdrawal of calcium antagonist therapy in outpatients and during bypass surgery in patients with prior angina at rest prompted the examination of the effect of nifedipine withdrawal in 81 patients who had completed a prospective, double-blind randomized trial of nifedipine versus placebo for rest angina. Thirty-nine patients underwent bypass surgery for uncontrolled angina or left main coronary artery disease. No significant difference between patients withdrawn from nifedipine or placebo was seen in the incidence of perioperative myocardial infarction, hypotension requiring intraaortic balloon counterpulsation, vasopressor or vasodilator requirements or incidence of significant arrhythmias. An additional 42 patients had completed 2 years on a protocol consisting of nitrates and propranolol in addition to nifedipine or placebo. During a mean of 66 hours of continuous monitoring after withdrawal of nifedipine or placebo, heart rate and blood pressure were unchanged. A worsening of previously present angina at rest occurred in five patients who had continued to experience rest angina before drug withdrawal, four of whom were withdrawn from nifedipine. No patient with class I to III angina experienced new onset of rest angina during drug withdrawal. No patient experienced myocardial infarction. There was no significant difference between patients withdrawn from nifedipine or placebo in the duration or frequency of ischemic ST changes on continuous electrocardiographic monitoring, or in duration or positive results of serial exercise treadmill testing. Thus, no early adverse effects of acute nifedipine withdrawal were found in patients with prior rest angina at the time of bypass surgery or in stable patients receiving long-term medical therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Unstable angina precipitated by nifedipine. A case report

A case of unstable angina pectoris precipitated by the administration of nifedipine, a complication which has not been well documented, is reported.