PubMed Health⌕ Search

Biomedical subjects

D F Kong

Publications and source records attributed to D F Kong.

At least 19 recordsLinked to original sources
PubMed2001

Risk factors associated with thrombosis in patients with antiphospholipid antibodies.

OBJECTIVE: To define risk factors associated with thrombosis in patients with antiphospholipid antibodies (aPL). METHODS: Ninety-nine patients with aPL, most of whom had prior thrombosis, were evaluated for the presence of acquired and inherited thrombophilic states. Genomic testing was performed for factor V(R506Q), 3' prothrombin (PTG) and methylene tetrahydrofolate reductase (MTHFR) polymorphisms. Clinical records were reviewed for the presence of acquired risk factors (RF) for thrombosis and events associated with aPL. Univariate statistical analysis was performed using Fisher's exact testing. A neural network statistical model was also used to identify which thrombophilic risk factors were most important in development of arterial and venous thrombosis. RESULTS: For arterial thrombosis, hypertension, tobacco use, hyperlipidemia, and diabetes mellitus were the most important predictors of thrombosis. By contrast, tobacco use, the 3' PTG and factor V(R506Q) polymorphisms, and previous cardiac surgery were the most important predictors of venous thrombosis. CONCLUSION: In this hypothesis-generating retrospective study, acquired risk factors were most important in arterial thrombosis, while the presence of factor V(R506Q) and 3' PTG polymorphisms were more important in the development of venous thrombosis. These findings are being validated in an ongoing, prospective study.

Adolescent↗
PubMed2000

Advances in the approach to acute coronary syndromes.

Acute coronary syndromes is a new term that encompasses the many permutations of acute ischemic heart disease. Management guidelines can help steer clinicians through diagnosis and facilitate rational selection of therapy from the myriad of available treatments.

Acute Disease↗
PubMed2000

Outcomes following interventions in small coronary arteries with the use of hand-crimped Palmaz-Schatz stents.

Although coronary stenting has been shown to be effective, retrospective studies have suggested that stents do not provide better results than angioplasty in small coronary arteries. We sought to examine procedural, in-hospital, and long-term outcomes of patients undergoing small-vessel stenting with Palmaz-Schatz stents hand-crimped on a balloon catheter <3 mm in diameter. We retrospectively analyzed the outcomes of 117 patients who underwent this type of coronary stent implantation at Duke University Medical Center between January 1, 1997 and May 30, 1998. The clinical indications for percutaneous revascularization included unstable angina in 67.5% of patients, acute myocardial infarction in 4.3%, postinfarct angina in 3.4%, silent ischemia in 3.4%, and stable angina in 1% of patients. Quantitative angiographic analysis was performed immediately before angioplasty and after stent implantation. Stents were used for elective indications in 24%, for suboptimal angiographic result in 61.5%, and for abrupt and/or threatened closure in 14.5% of patients. Reference vessel diameter was similar before and after the procedure. Minimum luminal diameter increased from 0.63 to 2.35 mm, an acute gain of 1.72+/-0.43 mm. Percent stenosis decreased from 74.2% to 4.7%. The clinical composite of death (n = 1, 1%), nonfatal myocardial infarction (n = 6, 5.1%), and revascularization (n = 1, 1%) occurred in-hospital in only 8 patients (6.8%), resulting in clinical procedure success in 109 patients (93%). Our data suggest that stents designed for vessels >3.0 mm can be deployed in small vessels, with a low in-hospital event rate. However, target lesion revascularization in small vessels remains high. Development of antiproliferative strategies could improve long-term outcomes for small-vessel interventions.

Aged↗
PubMed2000

Poststress measurements of left ventricular function with gated perfusion SPECT: comparison with resting measurements by using a same-day perfusion-function protocol.

PURPOSE: To investigate the relationship between the development of ischemia during stress testing and the changes in left ventricular ejection fraction (LVEF) measurements obtained after stress and at rest with a same-day perfusion-function imaging protocol. MATERIALS AND METHODS: One hundred twenty-six patients underwent a same-day rest-stress (61%) or stress-rest (39%) protocol and gated single photon emission computed tomography (SPECT). Perfusion analysis was performed with a 12-segment model. Defects were scored (0 = no defect, 1 = mild defect, 2 = moderate defect, and 3 = severe defect); differences between the summed stress and resting scores of greater than three indicated substantial ischemia. RESULTS: Resting and poststress LVEFs correlated significantly (r = 0.97, P <.001); however, patients with and patients without ischemia had significant differences in poststress versus resting LVEFs (-4.0 vs 1.0, respectively; P <.01). In patients with ischemia versus patients without ischemia, subgroup analysis stress-rest (-2.5 vs 1.0, P =.047) and rest-stress (-4.0 vs 1.0, P =.006) protocols yielded similar results. CONCLUSION: In patients with clinically important stress-induced perfusion abnormalities, the LVEF after stress was significantly lower than the LVEF at rest with same-day rest-stress and stress-rest imaging protocols. In the clinical setting, poststress LVEFs may be lower than true resting measurements, particularly in patients with moderate to severe stress-induced ischemia.

Adenosine↗
PubMed1999

Clinical outcomes of bivalirudin for ischemic heart disease.

BACKGROUND: Current treatment strategies for percutaneous coronary revascularization and acute coronary syndromes incorporate thrombin inhibition with either unfractionated or fractionated heparin. The peptide bivalirudin (Hirulog) is a direct thrombin inhibitor whose pharmacological properties differ from those of heparin. We conducted a systematic overview (meta-analysis) to assess the effect of bivalirudin on 4 end points: death, myocardial infarction, major hemorrhage, and the composite of death or infarction. METHODS AND RESULTS: Six trials (5674 patients) represent the randomized, controlled bivalirudin experience, including 4603 patients undergoing elective percutaneous coronary revascularization and 1071 patients with acute coronary syndromes. ORs for the 4 clinical end points were calculated for each trial. Four trials (4973 patients) that compared bivalirudin with heparin were combined with the use of a random-effects model. In these trials, bivalirudin was associated with a significant reduction in the composite of death or infarction (OR 0.73, 95% CI 0.57 to 0.95; P=0.02) at 30 to 50 days, or 14 fewer events per 1000 patients so treated. There also was a significant reduction in major hemorrhage for the same trials (OR 0.41, 95% CI 0. 32 to 0.52; P<0.001, or 58 fewer events per 1000 patients so treated). A similar analysis combined 2 dose-ranging trials (701 patients) that compared therapeutic (activated partial thromboplastin time more than twice the control time) with subtherapeutic bivalirudin anticoagulation (activated partial thromboplastin time less than twice the control time). CONCLUSIONS: Bivalirudin is at least as effective as heparin, with clearly superior safety. Thus, it provides an unprecedented net clinical benefit over heparin in patients with ischemic heart disease.

Anticoagulants↗
PubMed1999

Outcome of Hispanic patients treated with thrombolytic therapy for acute myocardial infarction: results from the GUSTO-I and III trials. Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries.

OBJECTIVES: We sought to describe the differences in the process of care and clinical outcomes between Hispanics and non-Hispanics receiving thrombolytic therapy for myocardial infarction (MI). BACKGROUND: Hispanics are the fastest growing and second largest minority in the U.S. but most cardiovascular disease data on Hispanics has been derived from retrospective studies and vital statistics. Despite their higher cardiovascular risk-factor profile, better outcomes after MI have been reported in Hispanics. METHODS: We studied the baseline characteristics, resource use and outcomes of 734 Hispanics and 27,054 non-Hispanics treated for MI in the GUSTO-I and -III trials. The primary end point of both trials was 30-day mortality. RESULTS: Hispanics were younger, shorter, lighter and more often diabetic and began thrombolysis 9 min later, compared with non-Hispanics. Measures of socioeconomic status (educational level, employment and health insurance) were lower among Hispanics. Fewer Hispanics than non-Hispanics underwent in-hospital angiography (70% vs. 74%, p = 0.013) or bypass surgery (11% vs. 13.5%, p = 0.04). Hispanics received more angiotensin-converting enzyme (ACE) inhibitors and less calcium-channel blockers, prophylactic lidocaine and inotropic agents. Mortality at 30 days and at one year did not differ significantly between Hispanics and non-Hispanics (6.4% vs. 6.7% and 9.0% vs. 9.7%, respectively). We noted no interactions between thrombolytic strategy and Hispanic status on major outcomes (30-day death, stroke and major bleeding). CONCLUSIONS: The care of Hispanics with MI differed slightly from that of non-Hispanics. Nevertheless, these differences in care did not affect long-term outcomes.

Aged↗
PubMed1999

Multicenter randomized trial and a systematic overview of lidocaine in acute myocardial infarction.

BACKGROUND: More than 20 randomized trials and 4 meta-analyses have been conducted on the use of prophylactic lidocaine in acute myocardial infarction (MI). The results suggest that lidocaine reduces ventricular fibrillation (VF) but increases mortality rates in acute MI. METHODS AND RESULTS: Patients with ST-elevation MI who were examined <6 hours after symptom onset (n = 903) were randomly assigned to either lidocaine or no lidocaine and to either streptokinase and heparin or heparin alone. Lidocaine was given as 4 boluses of 50 mg each every 2 minutes, then an infusion of 3 mg/min for 12 hours, then 2 mg/min for 36 hours. We compared the incidence of in-hospital death and ventricular arrhythmias. We then performed a meta-analysis of prophylactic lidocaine in acute MI that included these and prior trial results. The rates of VF and death with and without lidocaine were calculated for each trial, then odds ratios (OR) with confidence intervals (CI) were calculated for the risk of these events overall with and without lidocaine. Patients given lidocaine in the randomized study had significantly less VF (2.0% vs 5.7% without lidocaine, P =.004) and a trend toward increased mortality rates (9.7% vs 7.0%, P =.145). Meta-analysis revealed nonsignificant trends toward reduced VF (OR 0.71, 95% CI 0.47 to 1. 09) and increased mortality rates (OR 1.12, 95% CI 0.91 to 1.36) with lidocaine. CONCLUSIONS: Lidocaine reduces VF but may adversely affect mortality rates. The routine use of prophylactic lidocaine in acute MI is not recommended.

Anti-Arrhythmia Agents↗
PubMed1999

The health care burden of unstable angina.

Worldwide, UA represents a significant allocation of resources. UA represents a syndrome where not only do many therapies exist, but considerable clinical trial evidence has accumulated. Universal application of effective practice patterns is warranted if we are to successfully reduce the burden of UA. Economic analyses cannot resolve many of the underlying societal issues that affect decision making. Often, the acceptability of an economic burden is dependent on the willingness of both individuals and society to pay. In an interesting study, Chestnut et al evaluated the willingness of 50 patients to pay for avoiding a worsening of their angina symptoms. On average, the patients were willing to pay between $210 and $499 to avoid four to eight additional angina episodes each month. The "rule of rescue" suggests that society is often willing to pay large sums of money to save those in extreme need, such as the 55-year-old man rushed to the emergency department clutching his chest. Only recently has attention been paid to how much this disease entity costs us. Whereas the 1980s and 1990s saw a focus on costs, the next century will increasingly focus on value--obtaining the best health outcome for the dollars spent. Debate has shifted, at least in part, from purely financial costs to medical effectiveness and outcomes management. Continuing assessments of value of interventions and application of evidence based-management strategies permit rational selection of therapy and allow us best to bear the burden of UA.

Angina, Unstable↗
PubMed1999

Glycoprotein IIb/IIIa receptor antagonists in non-ST elevation acute coronary syndromes and percutaneous revascularisation: a review of trial reports.

Acute coronary syndromes and percutaneous coronary interventions share a common pathophysiological mechanism of intimal disruption and platelet aggregation. Glycoprotein (GP) IIb/IIIa receptor antagonists, which interrupt the final common pathway of platelet activation and aggregation, have been shown to have clear clinical benefit as acute therapy. Treatment of 1000 patients with parenteral formulations prevents at least 1 death, 20 deaths or myocardial infarctions (MIs), and 30 deaths, MIs or revascularisation procedures over a 30-day period. These benefits are sustained at 6 months. Clinical trials of oral formulations are underway. The challenges of dose, haemorrhage and thrombocytopenia must be surmounted before oral antagonists can be incorporated into clinical practice. Despite enrolment of thousands of patients in randomised trials of GPIIb/IIIa antagonists, much additional information is needed to refine the use of this therapy in practice. Application of this drug class will advance a new therapeutic standard for ischaemic heart disease.

Administration, Oral↗