Recent Science and Clinical Application of Nutrition to Coronary Heart Disease.

One of the greatest threats to mortality in industrialized societies continues to be coronary heart disease (CHD). Moreover, the ability to decrease the incidence of CHD has reached a limit utilizing traditional diagnostic evaluations and prevention and treatment strategies for the top five cardiovascular risk factors (hypertension, diabetes mellitus, dyslipidemia, obesity, and smoking). It is well known that about 80% of CHD can be prevented with optimal nutrition, coupled with exercise, weight management, mild alcohol intake, and smoking cessation. Among all of these factors, optimal nutrition provides the basic foundation for prevention and treatment of CHD. Numerous prospective nutrition clinical trials have shown dramatic reductions in the incidence of CHD. As nutritional science and nutrigenomics research continues, our ability to adjust the best nutrition with an individualized approach is emerging. This article reviews the role of nutrition in the prevention and treatment of CHD and myocardial infarction (MI).

Comparison of the usefulness of gadodiamide and iodine mixture versus iodinated contrast alone for prevention of contrast-induced nephropathy in patients with chronic kidney disease undergoing coronary angiography.

Contrast-induced nephropathy (CIN) is a common cause of hospital-acquired renal failure. Gadolinium-based contrast agents have been proposed as alternatives to iodinated contrast in patients at high risk for CIN. The use of high-dose intraarterial gadolinium chelates in the catheterization laboratory has been investigated in only a small number of patients. We compared patients with a creatinine clearance <60 ml/min/1.73 m2 who received intravenous hydration (> or =1,500 ml) and oral n-acetylcysteine prophylaxis with those who received a gadodiamide-iodine mixture (n = 90) or iodinated contrast alone (n = 79) in the cardiac catheterization laboratory. CIN was defined as an increase of 0.5 mg/dl in serum creatine from baseline. The 2 groups were similar with respect to demographics and risk factors. Although less iodinated contrast was used in the gadolinium mixture group, there was no difference in the incidence of CIN between the 2 groups. However, the initiation of dialysis (n = 7) and death (n = 8) only occurred in the diluted gadolinium contrast group. A stepdown multivariate analysis found diabetes mellitus to be the only independent predictor of CIN (p = 0.02, odds ratio 3.35, 95% confidence interval 1.21 to 9.29, c-statistic 0.66). In conclusion, the incidence of CIN was not decreased in high-risk patients receiving a gadolinium-iodinated contrast mixture versus iodinated contrast alone.

Stress testing in patients with implantable cardioverter-defibrillators: a preliminary report.

This retrospective study was undertaken to assess the responses to, and complications associated with, stress testing in patients with implantable cardioverter-defibrillators (ICDs). Primary end points were occurrence of malignant ventricular arrhythmias, onset of burst pacing or ICD firing, cardiopulmonary resuscitation, or death during or soon after stress testing. Secondary end points were urgent coronary revascularization and/or hospital readmission for cardiovascular complications. During a 4-year period, 1734 patients underwent ICD implantation or generator replacement at our institution; 84 patients (mean age +/- SD, 67+/-12 years; 76% men) subsequently underwent 107 stress tests, including 44 exercise and 63 pharmacologic (22 dobutamine, 41 dipyridamole) evaluations. None of the ICDs were inactivated before testing. All tests were supervised by specially trained paramedical personnel, with a physician immediately available. Four patients had self-terminating, nonsustained ventricular tachycardia at peak stress. None had sustained ventricular tachycardia requiring emergent therapy. There were no deaths or hospital readmissions for ventricular arrhythmias. These findings suggest that stress testing is feasible in patients with ICDs and that it can be performed without pretest inactivation.

Outcome of ventricular fibrillation developing during percutaneous coronary interventions in 19,497 patients without cardiogenic shock.

Ventricular fibrillation (VF) developing out of hospital or even in hospital has a reported prognosis for survival that is <50%. We examined the prognosis for VF in 19,497 patients undergoing percutaneous coronary intervention and identified 164 who had VF (0.84%). The time to defibrillation was <1 minute and was successful in all without sequelae. Thus, VF developing in the catheterization laboratory is unique in terms of prognosis.

Safety of percutaneous transfemoral coronary and peripheral procedures via aortofemoral synthetic vascular grafts.

Our objective was to evaluate the safety of percutaneous transfemoral catheterization performed by way of synthetic aortofemoral vascular grafts. Between 1994 and 2003, 123 catheterization procedures were performed using a synthetic aortofemoral graft (median graft age 2.5 years, range 4 days to 10.3 years), including 63 (51%) interventional and 60 (49%) diagnostic procedures. Adverse events related to vascular access occurred in 7 of 123 procedures (5.7%), including blood transfusion (4.1%), thrombotic occlusion (1.6%), transient limb ischemia (0.8%), and retroperitoneal hemorrhage (0.8%). No deaths, graft infections, or pseudoaneurysms occurred.

Evaluation of safety of warfarin in combination with antiplatelet therapy for patients treated with coronary stents for acute myocardial infarction.

The safety and efficacy of treating recently stented patients on combination antiplatelet therapy with warfarin for clinical indications in unknown. Therefore, we examined the use of warfarin in a population of patients with myocardial infarction (MI) treated with coronary stenting. We performed a retrospective analysis comparing patients who underwent successful coronary stenting for acute MI and were discharged on either warfarin and combination platelet therapy for clinical indications or combination antiplatelet therapy alone. There was a nonsignificant trend toward reinfarction at 6 and 12 months in warfarin-treated patients. Warfarin-treated patients had significantly higher rates of transfusion compared to nonwarfarin-treated patients at 12 months (21% vs 0%, P=0.028). There were no significant predictors of reinfarction in 6 and 12 months in multivariate analysis. These data demonstrate that warfarin anticoagulation, in combination with successful coronary stenting for acute MI and antiplatelet therapy, does not reduce risk of reinfarction but is associated with increased rates of transfusion.

Characteristics of cerebrovascular accidents after percutaneous coronary interventions.

OBJECTIVES: We sought to identify the incidence, predictors, and clinical implications of cerebrovascular accidents (CVAs) after percutaneous coronary interventions (PCIs). BACKGROUND: Cerebrovascular accidents after PCI, although rare, can be devastating. Limited information exists regarding the characterization of this complication. METHODS: The study population comprised 20,679 patients who underwent PCI between September 1993 and April 2002. A CVA was defined as a composite of transient ischemic attack (TIA) and stroke. The characteristics of those who had a periprocedural CVA were compared with those who did not. RESULTS: A CVA occurred in 92 patients (0.30% of procedures). Of these, TIA occurred in 13 patients (0.04%) and stroke in 79 patients (0.25%). On multivariate analysis, patients with this complication more frequently had diabetes mellitus (adjusted odds ratio [OR] 1.8, 95% confidence interval [CI] 1.1 to 3.0; p = 0.013), hypertension (OR 1.9, 95% CI 1.1 to 3.3; p = 0.033), previous CVA (OR 2.3, 95% CI 1.3 to 4.0; p = 0.0059), and creatinine clearance < or =40 ml/min (OR 3.1, 95% CI 1.8 to 5.2; p < 0.0001). They underwent urgent or emergent procedures (OR 2.7, 95% CI 1.3 to 5.5; p = 0.0092) with more thrombolytic (OR 4.7, 95% CI 2.3 to 9.7; p < 0.0001) and intravenous heparin (OR 1.9, 95% CI 1.1 to 3.4; p = 0.030) use before PCI, and they more often required emergent intra-aortic balloon pump placement (OR 2.2, 95% CI 1.1 to 4.3; p = 0.028). On multivariate analysis, CVA was independently associated with in-hospital death (OR 7.8, 95% CI 4.2 to 14.7; p < 0.0001), acute renal failure (OR 2.8, 95% CI 1.4 to 5.7; p = 0.0042), and new dialysis (OR 3.73, 95% CI 1.01 to 13.8; p = 0.049) after PCI. CONCLUSIONS: Cerebrovascular accidents after PCI, although rare, are associated with high rates of in-hospital death and acute renal failure, often requiring dialysis.

Predicting mortality in patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention (PAMI risk score).

We performed a pooled analysis of the Primary Angioplasty in Myocardial Infarction (PAMI) trials to examine predictors of death after primary percutaneous coronary intervention. Using these data, we developed a risk score with a range of 0 to 15 points. The PAMI risk score was found to be a strong predictor of late mortality.

Effectiveness of primary angioplasty for acute myocardial infarction in patients on dialysis.

We sought to characterize the outcome in patients who were on long-term dialysis and who underwent primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction. Of 2,831 consecutive patients who underwent primary PTCA for acute myocardial infarction from 1993 to 2001, 15 patients on long-term dialysis were identified. This small cohort had a 40% incidence of cardiogenic shock on admission. Despite the angiographic success rate for primary PTCA of 80%, in-hospital mortality was 53%.

The long-term consequences of lost intracoronary stents.

The aim of the study was to determine the incidence of lost or misplaced stents and to identify associated immediate- and long-term consequences. The study reviewed 11,881 cases with one or more intracoronary stents. From this group 40 cases were identified where stents were prematurely displaced from the stent delivery device. Sixteen were removed with bioptomes or snares. Three were removed surgically. Of the 21 remaining stents, 7 were deployed at a site remote from the target lesion and 14 were lost. Nine of the 14 were known to be below the aortoilliac bifurcation and the other 5 embolized to unknown locations. Stent loss is rare in intracoronary intervention. Removal or peripheral deployment is the best option, but there was no immediate or long-term morbidity associated with lost stents in this study.

Diagnosis, management, and clinical outcome of cardiac tamponade complicating percutaneous coronary intervention.

Cardiac tamponade is an uncommon but life-threatening complication of percutaneous coronary intervention (PCI). The purpose of the present study was to characterize the incidence, management, and clinical outcome associated with this complication. We analyzed a prospective database of 25,697 PCIs performed at William Beaumont Hospital (Royal Oak, Michigan) between October 1993 and December 2000. Cardiac tamponade was observed in 31 of 25,697 PCI procedures (0.12%). Cardiac tamponade was diagnosed in the catheterization laboratory in 17 of 31 patients (55%), and 14 patients (45%) had a delayed presentation (mean time from PCI 4.4 hours). Cardiac tamponade was twice as frequent after use of atheroablative devices compared with percutaneous transluminal coronary angioplasty and stenting (0.26% vs 0.11%, p <0.05). All patients with immediate cardiac tamponade had coronary artery perforation. In 11 of 14 patients with delayed tamponade (79%), no actual site of perforation could be identified. A moderate or large pericardial effusion was observed in 20 patients, and 9 had small effusions without typical echocardiographic features of tamponade. Pericardiocentesis was performed in 30 patients; 19 patients (61%) were treated successfully with aspiration alone, but 12 patients (39%) required further emergency surgical intervention. In-hospital complications included death (42%), emergency surgery (39%), myocardial infarction (29%), and transfusion (65%). Cardiac tamponade is an uncommon but important complication of PCI and is associated with high mortality and morbidity. Most cases are recognized in the catheterization laboratory, but delayed cardiac tamponade may occur and must be considered as a cause of late hypotension after PCI.

Primary percutaneous interventions for acute myocardial infarction in octogenarians: a single-center experience.

BACKGROUND: The majority of cardiovascular deaths occur in the elderly. The safety and results of primary infarct intervention in octogenarians is not well characterized. HYPOTHESIS: The purpose of this study was to compare the results of primary infarct intervention in octogenarians with those in younger patients during 1997-1998 and to compare these results to those obtained in octogenarians treated in 1991-1994. METHODS: During 1997-1998, 40 octogenarians were treated with primary infarct intervention and were compared with 60 randomly selected patients aged < 80 years treated during the same time period. The results in octogenarians were compared with the results in a group of 37 patients of similar age treated in 1991-1994. The baseline characteristics, procedural results, and hospital outcome were obtained from a prospectively designed interventional database at a busy single-center program. RESULTS: There was no significant difference in hospital survival between the two groups of patients treated in 1997-1998 although there was a trend toward higher mortality in the octogenarian group. Length of stay and use of intra-aortic balloon pumps were greater in the octogenarian group. When the results in octogenarians treated in 1997-1998 were compared with the group of 37 patients treated in 1991-1994, the hospital mortality declined from 27 to 10% (p = 0.05). CONCLUSIONS: There has been improvement in hospital mortality over the past decade for patients aged > or = 80 years treated with primary infarct intervention. Hospital resources and length of stay are greater for the octogenarian group. Ongoing research studies are comparing the results of thrombolytic therapy and primary intervention in aged patients.

Central venous catheters.

Preview Placement of a central venous catheter is not without risk. If the tip of the catheter either is inadvertently positioned within the heart or migrates into it, vascular erosions may develop and result in perforation and death. In this article, Dr Kahn gives the advantages and disadvantages of the usual routes of insertion and describes monitoring techniques. He also suggests methods of avoiding initial intracardiac placement.

Preoperative cardiac evaluation.

Preview Medical clearance for patients who need surgery is commonly requested of primary care physicians. A focused evaluation of the cardiovascular and other major body systems is the key to assessing preoperative risk. Which diagnostic tools and laboratory tests are most helpful? And which findings are most significant? The authors answer these questions and suggest ways primary care doctors can help minimize complications in the perioperative period.

Reversing coronary atherosclerosis.

Preview Results of recently completed and ongoing trials may change the thinking on how to treat atherosclerosis. For example, even faithful adherence to the American Heart Association step 2 diet may not halt progression of established coronary artery disease. Also, current goals of lipid-lowering therapy may be inadequate to reverse coronary artery narrowings. Dr Kahn describes studies that have used more drastic measures to control hyperlipidemia, the effects of these measures on coronary atherosclerosis, and clinical application of results.