Racial differences in responses to thrombolytic therapy with recombinant tissue-type plasminogen activator. Increased fibrin(ogen)olysis in blacks. The Thrombolysis and Angioplasty in Myocardial Infarction Study Group

Low-Dose Alteplase versus Conventional Anticoagulation to treat Submassive Pulmonary Embolism in Hispanic Patients

The use of low-dose tissue plasminogen activator (tPA) in Hispanic patients with submassive pulmonary embolism (PE) is understudied. The purpose of this study is to explore the use of low-dose tPA in Hispanic patients with submissive PE compared with counterparts that received heparin alone. We retrospectively analyzed a single-center registry of patients with acute PE between 2016 and 2022. Out of 72 patients admitted for acute PE and cor pulmonale, we identified six patients that were treated with conventional anticoagulation (heparin alone) and six patients who received low-dose tPA (and heparin afterward). We analyzed if low-dose tPA was associated with differences in length of stay (LOS) and bleeding complications. Both groups were similar in regard to age, gender, and PE severity (based on Pulmonary Embolism Severity Index scores). Mean total LOS for the low-dose tPA group was 5.3 days, compared with 7.3 days in the heparin group ( p  = 0.29). Mean intensive care unit (ICU) LOS for the low-dose tPA group was 1.3 days compared with 3 days in the heparin group ( p  = 0.035). There were no clinically relevant bleeding complications documented in either the heparin or the low-dose tPA group. Low-dose tPA for submassive PE in Hispanic patients was associated with a shorter ICU LOS without a significant increase in bleeding risk. Low-dose tPA appears to be a reasonable treatment option in Hispanic patients with submassive PE who are not at high bleeding risk (<5%).

Racial Disparity Among the Clinical Outcomes Post-Myocardial Infarction Patients: A Systematic Review and Meta-analysis

The clinical outcomes post-Myocardial Infarction (MI) between Black and White patients have not been well studied, with limited literature available. We conducted a meta-analysis to estimate the clinical outcomes between Black and White patients post-MI.We systematically searched the PubMed, Embase, and Scopus databases from inception until September 26, 2022. A total of 6 studies with 220,984 patients have been included in the analysis. The mean age of patients with White and Black race was 68.46 and 65.14 years, respectively. The most common comorbidity among White and Black patients was hypertension (53% vs 87.73%). Our analysis showed that the likelihood of all-cause mortality (OR, 0.71[95%CI: 0.56-0.91]), P=0.01] and stroke (OR, 0.74[95%CI: 0.67-0.81]), P<0.001] were significantly lower in white patients compared with black patients. However, Black patients had fewer utilization of CABG (OR, 1.38[95%CI: 1.19-1.62], P<0.001]) and PCI (OR, 1.31[95%CI: 1.101-1.68]), P=0.04] compared with White patients, while 30-day mortality was comparable between both the groups. To our knowledge, this is the first meta-analysis with the largest sample size thus far, highlighting that Black patients are at increased risk for all-cause mortality and stroke but have lower utilization of revascularization among MI patients than White patients.

Accelerated fibrin clot degradation is associated with arterial thromboembolism in patients following venous thrombosis: a cohort study

Several lines of evidence have suggested that patients following venous thromboembolism (VTE) are at higher risk of arterial thromboembolism (ATE). Prothrombotic fibrin clot characteristics were reported in individuals with cardiovascular risk factors. We investigated whether specific fibrin clot properties measured after 3-4 months of anticoagulation characterize VTE patients with subsequent ATE. We enrolled 320 patients following VTE aged below 70 years (median age, 46). Ten patients were lost to follow-up. ATE occurred in 21 individuals after a median 54 (31-68) months during a follow-up of 87.5 months (incidence 0.94%; 95% confidence interval [CI], 0.59-1.4 per patient-year). Patients with ATE had faster fibrin clot degradation, reflected by maximum rate of D-dimer increase during plasma clot lysis induced by tissue-type plasminogen activator (D-D_rate) at baseline. Clot permeability, turbidimetric variables, clot lysis time, and thrombin generation were unrelated to ATE. Univariable Cox proportional hazards analysis showed that age, diabetes, and D-D_rate were risk factors for subsequent ATE. Increased D-D_rate (by 0.001 mg/L/min; hazard ratio, 1.08; 95% CI 1.02-1.14) was an independent predictor of ATE after adjustment for potential confounders. Faster fibrin clot degradation at 3 months since VTE may increase the risk of ATE among VTE patients during follow-up.

Fibrin clot characteristics in acute ischaemic stroke patients treated with thrombolysis: the impact on clinical outcome

Fibrin clot properties in acute ischaemic stroke (AIS) are unfavourably altered, including faster formation of denser and poorly lysable fibre networks. We investigated clot properties in AIS patients treated with recombinant tissue plasminogen activator (rtPA) and their impact on clinical outcome. In 74 consecutive AIS patients eligible for rtPA treatment, we assessed ex vivo plasma fibrin clot formation, permeability (K_s), and rtPA-induced lysis, along with peak thrombin generation, fibrinolysis proteins and inhibitors at three time points - on admission, after 24 hours and 3 months since stroke. Clinical outcome was assessed using the NIHSS and mRS scores. Compared with the pretreatment values, fibrin networks assessed 24 hours since thrombolysis were formed more slowly (+20.5 % lag phase on turbidimetry), were less compact (+36.9 % K_s), composed of thinner fibres (-10.6 % lower maximum absorbancy [ΔAb]), which were lysed more rapidly (-20.8 % clot lysis time [CLT] and +7.1 % the rate of rtPA-induced D-dimer release from clots [D-D_rate]). Thrombin generation and fibrinolysis proteins remained elevated. Lower ΔAb (<0.86 at 405 nm), shorter CLT (<105 min), and higher D-D_rate (>0.072 mg/l/min) assessed at baseline predicted good outcome (mRS 0-2) at 3 months after adjustment for age and fibrinogen. Logistic regression adjusted for potential confounders showed that good outcome at 3 months was predicted by pretreatment D-D_rate, while pretreatment CLT predicted excellent outcome (mRS of 0-1). In conclusion, formation of denser fibrin clots displaying impaired lysability and pattern of their changes induced by thrombolysis may affect clinical outcome in AIS patients.

The need for a population-based, dose optimization study for recombinant tissue plasminogen activator in acute ischemic stroke: A study from a tertiary care teaching hospital from South India

Context:

The guideline recommended dose of intravenous (i.v) recombinant tissue-type plasminogen activator (rt-PA) for acute ischemic stroke is 0.9 mg/kg in the European and American populations. In Asiatic population, some studies have shown that a lower dose of i.v rt-PA is equally efficacious.

Aims:

To assess if there is a need for a dose optimization for i.v rt-PA study among Indians.

Setting and Design:

A prospective, observational database of acute stroke cases that presented to a tertiary care institute over a period of 1 year was made.

Methods:

The data procured using a prestructured elaborate pro forma. Based on the dose of rt-PA received, the individuals were divided into three groups; Group 1 (0.6–0.7 mg/kg), Group 2 (0.7–0.8 mg/kg), and Group 3 (0.8–0.9 mg/kg). Improvement was assessed in each group and between the thrombolysed and nonthrombolysed individuals.

Statistical Analysis Used:

The nonparametric Mann–Whitney U-test (Wilcoxon rank-sum test) was applied for assessing improvement of National Institutes of Health Stroke Scale score with significance level of α < 0.05 (P < 0.012) and compliance level at 95%.

Results:

Between the thrombolysed (n = 46) and nonthrombolysed (n = 113) group, there was a statistically significant neurological improvement in the thrombolysed group. Clinical improvement was noted in 75%, 85.7%, and 66.7% of individuals receiving rt-PA in Groups 1, 2, and 3, respectively. Four out of the five who developed a clinically significant intracranial hemorrhage were thrombolysed at a dose of 0.8–0.9 mg/kg rt-PA (Group 3).

Conclusion:

There is a need for a properly randomized, dose optimization study of i.v rt-PA in the Indian subcontinent.

The challenges of treating peripheral arterial disease

Today, peripheral arterial disease (PAD) patients need effective medical care for an extended period of their lifetime. Therefore, different treatment modalities have to be tied sequentially into an effective therapeutic chain. First, preventive measures have to be reinforced and risk factors tightly controlled. Furthermore, antiplatelet agents have to be applied in every PAD patient to reduce the risk of cardiac and cerebral ischemic events, restenosis or reocclusion after revascularization, and possibly also progression of the PAD itself. Angiotensin-converting enzyme (ACE) inhibitors should be entertained in high-risk groups such as PAD patients with diabetes. In the claudicant, exercise therapy should be strongly encouraged and vasoactive drugs considered for those who are not good candidates for either exercise training or revascularization. In patients with disabling claudication or critical limb ischemia, revascularization procedures are highly effective. Especially for high-grade stenoses or short arterial occlusions, percutaneous transluminal angioplasty (PTA) should be the method of fi rst choice followed by the best surgical procedure later on. To achieve good long-term effi cacy, a close follow-up including objective tests of both the arterial lesion and hemodynamic status, surveillance of secondary preventive measures and risk factor control is mandatory.

Current state of endovascular treatment of femoro-popliteal artery disease

Considerable advances have been made over the last decade in percutaneous technology for the treatment of atherosclerotic diseases in the femoro-popliteal arteries. While treatment strategies are well defined in the iliac segment, where angioplasty and stenting perform well in appropriately selected lesions, the search for a durable transcatheter therapy for femoro-popliteal lesions continues. Whereas balloon angioplasty (PTA) is the accepted therapy for short lesions, long diffuse lesions are still recommended for surgical treatment. However, attractive new technologies ranging from transcatheter plaque excision to laser ablation, rotational atherectomy, cryoplasty, brachytherapy, and placement of drug-eluting stents to simple angioplasty with drug-coated balloons may have the potential to replace femoro-popliteal bypass surgery as a treatment of choice for complex lesions. This article reviews the status of percutaneous endovascular techniques for the treatment of femoro-popliteal artery occlusive disease.

Clinical Experience with a New Nitinol Self-Expanding Stent in Peripheral Arteries

Purpose:

To evaluate a new self-expanding nitinol coil stent in stenotic or occluded peripheral arteries.

Methods:

Seventy-three symptomatic patients (58 men; mean age 67 years) were treated with nitinol stents for lesions in the iliac artery (9 stenoses); superficial femoral artery (SFA) (39 stenoses, 6 occlusions); popliteal artery and tibioperoneal trunk (9 stenoses, 7 occlusions); and 3 bypass grafts. Mean diameter stenosis was 84.4% ± 9.9% (range 75% to 100%), and mean lesion length was 45 ± 23 mm (range 20 to 120 mm).

Results:

Eighty-eight 40-mm-long stents with diameters between 5 and 8 mm were implanted percutaneously for suboptimal dilation (n = 45); dissection (n = 21); and restenosis (n = 7). All stents but one were implanted successfully; the malpositioned stent was removed, and another stent was successfully deployed. There were 3 (4.1%) failures due to thrombosis at 24 hours. During the mean 16-month follow-up (range to 44 months), 4 restenoses (3 femoral, 1 popliteal) have occurred; 2 were treated with repeat dilation and 2 underwent bypass. Primary and secondary patency rates at 18 months were 87% and 90%, respectively, for all lesions (iliac: 100% for both; femoral: 85% and 88%; popliteal: 87% and 100%).

Conclusions:

This new nitinol stent seems to be safe and effective with favorable long-term results, even in distal SFA lesions and popliteal arteries. Its flexibility and resistance to external compression allow its placement in tortuous arteries and near joints.

Initial Experience with the Cragg Endopro System 1 for Intraluminal Treatment of Peripheral Vascular Disease

Purpose:

To evaluate the safety and efficacy of a new covered stent, the Cragg Endopro System 1, for intraluminal treatment of peripheral vascular disease in the iliac and femoropopliteal arteries.

Methods:

Forty symptomatic patients with predominantly lengthy stenotic (24) or occlusive (13) lesions or aneurysms (3) in the iliac (19), femoral (19), or popliteal (2) arteries were treated percutaneously with balloon angioplasty followed by implantation of the self-expanding nitinol Cragg stent covered by a woven polyester fabric coated with low-molecular-weight heparin. The mean length of femoropopliteal lesions was 13.0 ± 1.8 cm, as compared to 6.7 ± 0.8 cm (p < 0.01) for iliac lesions. Mean percent stenosis was 89% ± 2% with no significant difference between the arterial segments.

Results:

With a total of 52 covered stents implanted, technical success was achieved in 98% (39/40 patients). One tortuous femoral artery aneurysm was not satisfactorily excluded to prevent leakage. Clinical success was seen in all patients with demonstrable improvements in the claudication stage and the ankle-brachial index from a mean 0.54 to 0.92. Three local complications (one hematoma, two false aneurysms) required surgical repair. One distal embolism, one acute thrombosis, and three subacute thromboses were encountered and successfully treated by thrombolysis and/or surgery. One patient with two iliac stents developed contralateral common iliac artery occlusion from a stent partially obstructing the aorta; placement of a covered stent in the blocked artery re-established normal flow. Over an 8-month follow-up with arteriographic re-examination, all iliac stents remained patent. At the femoropopliteal level, two stents were occluded at 4 months; one was successfully dilated, but the other required surgical bypass grafting. A third patient developed a stenotic lesion proximal to the stent; dilation restored adequate inflow to the stent.

Conclusions:

The Cragg Endopro System 1 appears to be effective as an “internal bypass” for iliac and femoropopliteal occlusive disease. More complications and restenosis were seen in femoropopliteal implantations; however, a change in postoperative medication may improve these results. Long-term results will determine if the Cragg Endopro System 1 can achieve a patency equal to conventional bypass grafting.

The Mollring Cutter™ Remote Endarterectomy: Preliminary Experience with a New Endovascular Technique for Treatment of Occlusive Superficial Femoral Artery Disease

Purpose:

To evaluate the feasibility and efficacy of the Mollring Cutter™ remote endarterectomy (EA) technique in the treatment of occlusive superficial femoral artery (SFA) disease.

Methods:

A new device was developed to perform remote EA of occluded SFAs through a single groin incision. The technique initially uses a conventional ring stripper, which is exchanged for a double-ring cutter that transects the distal atheroma core. The entire core and cutter are removed simultaneously, and a Palmaz stent is implanted to secure the distal intimal flap.

Results:

Twenty-six consecutive patients with disabling claudication or critical ischemia were treated for long segment occlusions (n = 23) and multiple stenoses (n = 3). Patients were evaluated on the intention-to-treat basis. Clinical and anatomic success was achieved in all 26 SFAs. Average length of the endarterectomized segments was 29.9 cm (range 23 to 41). Technical problems were encountered intraoperatively in four patients, including one who required a second incision at the distal SFA to retrieve a broken ring. Recovery was uneventful in all patients. At up to 6-month follow-up, one reocclusion has been seen at 5 months.

Conclusions:

Based on this early experience, remote EA with the Mollring Cutter appears to be a feasible and effective method for treating occlusive SFA disease. Obviating the need for a second incision at knee level, this technique offers a less invasive approach that should facilitate postoperative recovery and earlier discharge.

Endoluminal Grafting for Aneurysmal and Occlusive Disease in the Superficial Femoral Artery: Early Experience

Purpose:

To examine whether endoluminal grafts (ELGs) of radially expandable polytetrafluoroethylene (PTFE) can successfully form durable internal conduits to revascularize lengthy occlusive disease and exclude aneurysms in the femoropopliteal (FP) arteries.

Methods:

Under protocol, implantation of an unpredilated PTFE tube ELG anchored with Palmaz stents using a low-profile percutaneous delivery system was attempted in 50 symptomatic patients for a variety of pathologies: (1) restenosis; (2) complex lesions unlikely to be treated successfully with other endoluminal therapies; (3) acute angioplasty failure; and (4) aneurysms. There were 37 occlusions, 14 stenoses, and 2 long, combined stenoticaneurysmal lesions in 47 native arteries, 5 FP grafts, and 1 femorotibial (FT) vein graft. Thirty-two percent of the patients had ≤ 1 vessel runoff. The average lesion length was 20.4 ± 11.4 cm (range 1.5 to 40), and the mean preoperative ankle-brachial index (ABI) at rest was 0.53 ± 0.14.

Results:

In a 20-month period through April 1995, 50 patients (34 males, 16 females; mean age 69.5 years, range 45 to 87) underwent 54 procedures in 53 limbs; 55 ELGs were successfully deployed in 51 limbs; 2 patients were converted to FP bypass owing to technical problems (96% procedural success). There were 18 inhospital complications: 1 distal wire dissection repaired with an additional ELG; 2 hematomas requiring surgical repair; 1 graft collapse; 1 pseudoaneurysm at the site of a mid-ELG leak; 7 minor access sequelae; and 6 acute ELG thromboses, 4 treated with lytic therapy and balloon dilation, 1 with open thrombectomy, and 1 with bypass grafting. The mean postoperative ABI was 1.01 ± 0.10. During the 30-day postprocedure period, 2 ELGs rethrombosed and 2 other limbs (3 ELGs) occluded; 1 thrombosis and 1 rethrombosis were lysed successfully, but the other 2 patients had an FP bypass. Over the mean 8.3 ± 5.5 month follow-up, 6 additional ELGs occluded and 1 reoccluded; 4 were successfully treated by endovascular techniques for a primary patency of 72% and secondary patency of 84% by life-table analysis.

Conclusions:

Endovascular grafting is a conceptually attractive technique that has the potential to expand the current boundaries of interventional treatment. This preliminary experience attests to the feasibility and safety of ELG deployment in the superficial femoral arteries. Whether such a device can match the durability of classical revascularization techniques remains to be determined in clinical trials when device configurations and deployment techniques have been standardized.

Long-term Results with the Palmaz Stent in the Superficial Femoral Artery

Purpose:

Femoral stenting has demonstrated inconsistent and often disappointing long-term results. To compare our experience, we retrospectively analyzed a series of patients who had Palmaz balloon-expandable stents placed exclusively for superficial femoral artery (SFA) lesions.

Methods:

From January 1990 to November 1993, 39 patients were evaluated for claudication (79%) or critical ischemia in 42 limbs. The culprit lesions were confined to the SFA: 24 (57%) occlusions and 18 (43%) stenoses, including 3 restenotic lesions. Stenting was elective in 12 (29%) cases: the 3 restenoses and 9 chronic, calcified occlusions. The remaining stents were applied for postangioplasty residual stenosis or angioscopic findings of thrombogenic luminal irregularities. A total of 55 prostheses were successfully implanted. All patients were maintained on ticlopidine and followed by routine duplex scanning. Follow-up angiography was performed in 28 (72%) patients between 4 and 45 months.

Results:

In the postprocedural period, two acute thromboses (4.8%) occurred within 48 hours in patients who had long occlusions and poor runoff; no other major complications were encountered, for a clinical success rate of 95%. Follow-up evaluation ranged from 4 months to 4 years with a mean of 25 months. The restenosis rate was 19% (34% in occlusions; 10% in stenotic lesions, p = NS). At 24 months, cumulative primary patency was 77% and secondary patency 89%.

Conclusions:

Palmaz stents performed well in the SFA, demonstrating a low acute thrombosis rate and good long-term patency. The incidence of restenosis is likely to be greater in occlusions than in stenoses.

Thrombolysis in chinese ischemic stroke patients with renal dysfunction

BACKGROUND

Current data concerning the relationship between renal function and clinical outcome among stroke patients treated with intravenous thrombolytic therapy are conflicting. Our aim is to analyze whether the clinical outcome of Chinese ischemic stroke patients treated with thrombolytic therapy is affected by the presence of renal dysfunction.

METHODS

Chinese patients who received intravenous thrombolytic therapy for acute ischemic stroke were recruited. Renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) <90 ml/min/1.73 m(2). The primary outcome was independent function (modified Rankin Scale, mRS, 0-2) at 3 months, while secondary outcomes included early improvement of the National Institute of Health Stroke Scale (NIHSS) score of ≥4 points at 24 h, symptomatic intracerebral hemorrhage (ICH) within 36 h of treatment and 30-day mortality.

RESULTS

A total of 199 patients were recruited, of whom 51.3% had renal dysfunction. There were no significant differences in functional independence at 3 months, NIHSS improvement at 24 h post-thrombolysis and 30-day mortality between patients with or without renal dysfunction. Multivariate analysis showed that eGFR as a continuous variable was not an independent risk factor for symptomatic ICH.

CONCLUSION

Chinese ischemic stroke patients with renal dysfunction who received thrombolytic therapy had clinical outcomes similar to those without renal dysfunction.

Influence of racial differences on outcomes after thrombolytic therapy in acute ischemic stroke

BACKGROUND

The National Institutes of Neurological Disorders and Stroke and the European Co-operative Acute Stroke III trials enrolled a largely Caucasian population, but the results are often extrapolated onto non-Caucasians. A limited number of nonrandomized studies have proposed that non-Caucasian patients show differential response to tissue plasminogen activator.

AIMS AND/OR HYPOTHESIS

We examined if non-Caucasian patients of mixed national origin within the Virtual International Stroke Trials Archives neuroprotection trials responded differently to tissue plasminogen activator compared with Caucasians.

METHODS

We matched patients within each race-subtype for age, baseline National Institutes of Health Stroke Scales, and diabetes status, and excluded outliers. We tested for an interaction of race ethnicity with tissue plasminogen activator on predicting outcomes at α = 0·05. We compared 90-day ordinal outcome (modified Rankin Scale; primary analysis) and dichotomized outcomes (modified Rankin Scale 0-1; modified Rankin Scale 0-2; survival) within individual race ethnicity.

RESULTS

One thousand nine hundred forty-six thrombolysed patients (125 Blacks, 39 Asians, and 1821 Caucasians) were matched with 1946 non-thrombolysed patients in each race ethnicity group. Postmatching, there were no imbalances in baseline National Institutes of Health Stroke Scales and age between the groups (P > 0·05). The interaction of tissue plasminogen activator with race ethnicity was nonsignificant in ordinal (P = 0·4) and in dichotomized outcome models (P > 0·05). Ordinal odds for improved outcomes were 1·5 for all patients (P < 0·05). Ordinal odds for Caucasians were 1·5 (P < 0·05); for Blacks, 2·1 (P < 0·05); and for Asians, 1·2 (P > 0·05; 1·6 after 1:2 matching with nonthrombolysed, because of small numbers). Dichotomized functional outcomes improved after thrombolysis overall, in Caucasians, in Blacks (modified Rankin Scale 0-2 only), and in Asians (after 1:2 matching; P > 0·05). Odds for survival were consistent across all groups.

CONCLUSIONS

These results do not suggest a differential response to tissue plasminogen activator based on race ethnicity. Among Asians, data were particularly sparse, and results should be interpreted with caution.

Racial/Ethnic differences in poststroke rehabilitation outcomes

Background. Significant racial and ethnic disparities in stroke incidence, severity, and morbidity have been consistently reported; however, less is known about potential differences in poststroke rehabilitation outcomes. Objective. To examine racial and ethnic differences in poststroke rehabilitation outcomes. Methods. We completed an in-depth search of Medline and several major journals dedicated to publishing research articles on stroke, rehabilitation, and racial-ethnic patterns of disease over a 10-year period (2003–2012). We identified studies that reported rehabilitation outcomes and the race or ethnicity of at least two groups. Results. 17 studies involving 429,108 stroke survivors met inclusion criteria for the review. The majority (94%) of studies examined outcomes between Blacks and Whites. Of those studies examining outcomes between Blacks and Whites, 59% showed that Blacks were generally less likely to achieve equivalent functional improvement following rehabilitation. Blacks were more likely to experience lower FIM gain or change scores (range: 1–60%) and more likely to have lower efficiency scores (range: 5–16%) than Whites. Conclusions. Black stroke survivors appear to generally achieve poorer functional outcomes than White stroke survivors. Future studies are warranted to evaluate the precise magnitude of these differences, whether they go beyond chance, and the underlying contributory mechanisms.

Postthrombolysis Outcomes in Acute Ischemic Stroke Patients of Asian Race-Ethnicity

Background

Race-ethnic differences may influence postthrombolysis outcomes in acute ischemic stroke patients. Guidelines for thrombolytic therapy to treat Asian stroke patients are based mostly on extrapolated western data.

Aims

We undertook to examine outcomes among Asians by comparing a propensity-matched cohort of thrombolyzed patients from a tertiary center in Singapore with nonthrombolyzed Asian comparators collated from Virtual International Stroke Trials Archives (control).

Methods

We identified propensity scores-matched patients between thrombolyzed and control Asian patients lodged in the Virtual International Stroke Trials Archives by employing propensity scores method. We compared matched patients for their distributions of three-month functional (modified Rankin scores) and neurological outcomes (National Institute of Health Stroke Scale) by employing Cochran–Mantel–Haenszel test and proportional odds logistic regression analysis. We report odds ratio and 95% confidence interval for improved outcomes on day 90.

Results

Virtual International Stroke Trials Archives and National University Hospital, Singapore, contributed 517 and 133 patients of Asian race-ethnicity ( n = 650), respectively. After propensity matching, sample size reduced to 237 patients; 104 were from Virtual International Stroke Trials Archives. Age (59·7 vs. 61·5 years, P = 0·2) and mean baseline National Institute of Health Stroke Scale scores were similar ( 14 ) between thrombolyzed and control. The odds ratio for shift toward improved modified Rankin scores and National Institute of Health Stroke Scale distributions after tissue plasminogen activator therapy were 2·8 (95% confidence interval 1·8–4·5, P < 0·0001, n = 233; Cochran–Mantel–Haenszel P < 0·0001) and 2·8 (95% confidence interval 1·7–4·7, P = 0·0008, n = 201; Cochran–Mantel–Haenszel P = 0·0001).

Conclusions

Our data indicate that Asian patients derive benefit from thrombolytic therapy.

Gender Differences in Outcome after Stent Treatment of Lesions in the Femoropopliteal Segment

Background and Aims:

Although endovascular stent treatment is increasingly used in infrainguinal atherosclerotic occlusive disease, outcome with focus on gender differences has not been reported in detail.

Material and Methods:

One hundred and twelve consecutive patients (67 [60%]) women, undergoing endovascular nitinol stent treatment of atherosclerotic lesions in the femoropopliteal segment were analysed concerning improvement in ankle brachial index (ABI), reinterventions, complications, amputation and survival rates up to 12 months after intervention. Risk factors for amputation and death were analyzed with logistic regression.

Results:

At presentation, women showed critical limb ischemia (CLI) more often than men (87% vs. 58 %; P = 0.001). After 12 months ABI had improved (from 0.40 ± 0.26 at baseline to 0.86 ± 0.22 after 12 months, P < 0.001), but 16 patients (15%) had been amputated and 27 patients (24 %) had died. After adjustment for age, diabetes mellitus and smoking, female gender was an independent risk factor for amputation (OR 9.0; 95% CI 1.1–76.5; P = 0.045).

Conclusions:

Stent treatment of lesions in the femoropopliteal segment had favourable effects on ABI and limb salvage. Treated women more often had CLI and ran a higher risk for amputation within 12 months than men. This might reflect failure of clinicians to adequately appreciate symptoms of atherosclerotic leg artery disease in women.

A randomised controlled trial of antiplatelet therapy in combination with Rt-PA thrombolysis in ischemic stroke: rationale and design of the ARTIS-Trial

Background

Thrombolysis with intravenous rt-PA is currently the only approved acute therapy for ischemic stroke. Re-occlusion after initial recanalization occurs in up to 34% in patients treated with rt-PA, probably caused by platelet activation. In acute myocardial infarction, the combination of thrombolysis and antiplatelet therapy leads to a greater reduction of mortality compared to thrombolysis alone. In patients with acute ischemic stroke, several studies showed that patients already on antiplatelet treatment prior to thrombolysis had an equal or even better outcome compared to patients without prior antiplatelet treatment, despite an increased risk of intracerebral bleeding. Based on the fear of intracerebral haemorrhage, current international guidelines recommend postponing antiplatelet therapy until 24 hours after thrombolysis. Remarkably, prior use of antiplatelet therapy is not a contra-indication for thrombolysis. We hypothesize that antiplatelet therapy in combination with rt-PA thrombolysis will improve outcome by enhancing fibrinolysis and preventing re-occlusion.

Methods/Design

ARTIS is a randomised multi-center controlled trial with blind endpoint assessment. Our objective is to investigate whether immediate addition of aspirin to rt-PA thrombolysis improves functional outcome in ischemic stroke. Patients with acute ischemic stroke eligible for rt-PA thrombolysis are randomised to receive 300 mg aspirin within 1.5 hours after start of thrombolysis or standard care, consisting of antiplatelet therapy after 24 hours. Primary outcome is poor functional health at 3 months follow-up (modified Rankin Scale 3 - 6).

Discussion

This is the first clinical trial investigating the combination of rt-PA and acute aspirin by means of a simple and cheap adjustment of current antiplatelet regimen. We expect the net benefit of improved functional outcome will overcome the possible slightly increased risk of intracerebral haemorrhage.

Trial registration

The Netherlands National Trial Register NTR822. The condensed rationale of the ARTIS-Trial has already been published in Cerebrovascular Diseases.

Predictive factors of femoropopliteal patency after suboptimal duplex-guided balloon angioplasty and stenting: is recoil a bad sign?

Currently, the value of stenting during femoropopliteal balloon angioplasty (FPBA) remains unclear. Herein we evaluate the patency rates of successful duplex-guided balloon angioplasty (DAGBA) alone versus suboptimal DAGBA followed by stenting and the prestenting dissection versus recoil as potential indicators of stent success or failure. Over a period of 27 months, we performed 291 duplex-guided FPBAs (194 stenoses; 97 occlusions) on 244 limbs in 220 patients. Disabling claudication was the indication in 67%. Critical limb ischemia was the indication in the remaining 33%. Self-expanding nitinol stents were used when plaque dissection and/ or recoil caused diameter reduction > or = 40%. Serial follow-up duplex scans were obtained. Severe restenosis (> 70%) was measured by B-mode imaging and a peak systolic velocity ratio > 3. Follow-up ranged from 1 to 41 months (mean 10 +/- 8.3 months). The overall mean interval for restenosis and occlusion was 6.5 +/- 4.2 months and 5.6 +/- 6.1 months, respectively. Stents did affect overall patency results compared with not using stents. Reasons for stenting were plaque recoil, dissection, or both in 98 (53%), 44 (24%), and 42 (23%) cases, respectively. Six-month patency was 59%, 94%, and 69%, respectively. The difference between plaque recoil and dissection was significant (p<.04). The use of stents during FPBA may be associated with balloon angioplasty site failure in the femoropopliteal segment. To our knowledge, this is the first report ever to document plaque recoil as a predictor of balloon angioplasty site failure notwithstanding stent placement.

Comparison of five-year outcome in African Americans versus Caucasians following percutaneous coronary intervention

BACKGROUND

Studies regarding short-term outcomes after percutaneous coronary intervention (PCI) have reported no ethnic differences and data on long-term follow-up is conflicting and sparse.

METHODS

730 consecutive patients (67% African American) undergoing PCI from January 1999 to December 2000 at a tertiary care center in Detroit, MI, were followed up. End points studied included either all cause mortality collected from Social Security Death Index or first hospital admission after the index procedure due to myocardial infarction(MI), congestive heart failure(CHF), and revascularization (PCI or coronary artery bypass graft surgery).

RESULTS

African-Americans undergoing PCI had significant differences in baseline cardiovascular co-morbidity and were more likely to present with acute myocardial infarction than Caucasians. On Kaplan Meier survival analysis and log rank test, each ethnic group had equivalent survival for cumulative end points upto 6-month follow-up, however longer follow-up to 5 year was characterized by lower survival rate in African Americans compared to Caucasians (41% vs. 54%, log rank P 0.01). After adjustment for potential confounders, AA ethnicity (Adjusted HR 1.62, 95% CI 1.01-1.28, P 0.04) remained a predictor of adverse cardiac outcome (Death/MI/CHF) at five-year follow-up (Cox regression propensity adjusted hazard analysis).

CONCLUSIONS

African American patients undergoing PCI had unfavorable baseline cardiovascular characteristics but comparable short-term outcome compared to whites. However, at 5-year follow-up, African Americans had worse clinical outcome, higher incidence of acute myocardial infarction, congestive heart failure and significantly lower long-term survival.

Current status of heroic limb salvage for critical limb ischemia

The treatment of chronic lower extremity peripheral arterial disease is in a state of flux. During the past decade, vascular surgeons have assumed the responsibility for the endovascular care of patients needing vascular intervention. Once surgeons began performing these procedures, a change in attitude toward angioplasty resulted in an "endovascular explosion" and an overall reassessment of the traditional approaches to critical limb ischemia. Our current method of assessing outcomes is also in a state of flux. The original measure of procedural success, reconstruction patency, has been found to be a poor predictor of both patient palliation and functional success. A shift toward determining more accurate, patient-oriented outcome measures is ongoing. Until then, evidence would suggest that there are patients with such severe medical comorbidities, which include impaired ambulatory ability at presentation, that the benefits of revascularization seem to be insignificant. As our patient population ages and our healthcare system continues to fail financially, economic rationing motivated by lack of evidence-based data to the contrary may dictate that these patients are best served by primary limb amputation.

Meta-analysis comparing reported frequency of atrial fibrillation after acute coronary syndromes in Asians versus whites

The development of atrial fibrillation (AF) in cardiac patients is multifactorial, including not well defined genetic factors. To determine if Asian ethnicity is associated with the development of AF in patients with coronary disease, a meta-analysis was conducted of patient-level data from 7 prospective randomized clinical trials that prospectively collected information on the development of AF: 3 trials in patients with ST-elevation myocardial infarction (Global Use of Strategies to Open Occluded Coronary Arteries [GUSTO] I, GUSTO III, and GUSTO V), 3 trials in patients with non-ST-elevation acute coronary syndromes (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy [PURSUIT], Integrilin to Minimize Platelet Aggregation and Coronary Thrombosis-II [IMPACT II], and Platelet IIb/IIIa Antagonist for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network [PARAGON A]), and 1 trial in patients with both conditions (GUSTO IIb). A total of 94,785 patients were identified (93,050 white, 1,735 Asian). At baseline, Asian patients were younger; had lower body mass indexes; had a lower prevalence of female gender, previous angioplasty, and previous coronary artery bypass grafting; and had a greater prevalence of diabetes compared with white patients. The development of AF was lower in Asian than in white patients (4.7% vs 7.6%, p <0.001), while rates of ventricular tachycardia and fibrillation were similar in the 2 groups. In multivariate logistic regression analysis, Asian ethnicity was associated with significantly lower rates of AF (odds ratio 0.65, 95% confidence interval 0.50 to 0.84, p = 0.001) compared with white ethnicity. In conclusion, similar to previous studies showing a lower incidence of AF in non-Caucasian populations, Asians experiencing acute ischemic syndromes have a significantly lower frequency of AF compared with whites. Further study is needed to investigate the mechanisms and potential genetic underpinnings behind this association.

Comparison of Selective AT1-Receptor Blockade Versus ACE Inhibition for Restenosis Prophylaxis in Patients With Peripheral Occlusive Arterial Disease After Stent Angioplasty: A Randomized, Controlled, Proof-of-Concept Study

Different components of the renin-angiotensin system (RAS) have been demonstrated in atherosclerotic plaques. However, the involvement of the RAS in the complex process of in-stent restenosis is not yet clear. In this prospective, randomized, double-blind, controlled proof-of-concept study, we compared the 2 different pharmacological approaches, selective AT1-receptor-blockade with candesartan vs ACE inhibition with quinapril to reduce in-stent restenosis after stent angioplasty of the superficial femoral artery. Twenty-two hypertensive patients with stage IIb peripheral occlusive arterial disease and severe claudication who had been successfully treated with percutaneous transluminal angioplasty (PTA) and stent implantation were randomly assigned to receive daily doses of either candesartan (32 mg) or quinapril (20 mg). Primary end point was restenosis 6 months after intervention, assessed by angiography. Secondary end points were pain-free walking distance, determined by treadmill ergometry; determination of crurobrachial indices; and intima-media thickness (IMT). At 6 months, the rate of restenosis on angiography was 34% in the candesartan group and 71% in the quinapril group (P = .043). Relevant restenosis was found in 3 patients (27%) in the candesartan group and in 7 patients (64%) in the quinapril group. Patients in the candesartan group were able to walk farther on a treadmill (increase: 135 m ± 20 m) compared with patients in the quinapril group (increase: 83 m ± 21 m). The IMT at the stent edge was not significantly different in the 2 groups (candesartan: 1.9 mm ± 0.5 mm; quinapril: 2.0 mm ± 0.3 mm). This study revealed significant benefit of a pharmacological restenosis regimen using the AT1-receptor antagonist candesartan in patients with severe atherosclerosis after superficial femoral artery stenting compared with treatment with the ACE inhibitor quinapril. Further prospective studies in patients are required to confirm these results.

Ethnicity and cardiovascular disease prevention in the United Kingdom: a practical approach to management

The United Kingdom is a diverse society with 7.9% of the population from black and minority ethnic groups (BMEGs). The causes of the excess cardiovascular disease (CVD) and stroke morbidity and mortality in BMEGs are incompletely understood though socio-economic factors are important. However, the role of classical cardiovascular (CV) risk factors is clearly important despite the patterns of these risk factors varying significantly by ethnic group. Despite the major burden of CVD and stroke among BMEGs in the UK, the majority of the evidence on the management of such conditions has been based on predominantly white European populations. Moreover, the CV epidemiology of African Americans does not represent well the morbidity and mortality experience seen in black Africans and black Caribbeans, both in Britain and in their native African countries. In particular, atherosclerotic disease and coronary heart disease are still relatively rare in the latter groups. This is unlike the South Asian diaspora, who have prevalence rates of CVD in epidemic proportions both in the diaspora and on the subcontinent. As the BMEGs have been under-represented in research, a multitude of guidelines exists for the 'general population.' However, specific reference and recommendation on primary and secondary prevention guidelines in relation to ethnic groups is extremely limited. This document provides an overview of ethnicity and CVD in the United Kingdom, with management recommendations based on a roundtable discussion of a multidisciplinary ethnicity and CVD consensus group, all of whom have an academic interest and clinical practice in a multiethnic community.

Subclinical coronary atherosclerosis: racial profiling is necessary!

OBJECTIVES

We aim to review the studies comparing coronary calcification across different ethnic groups.

BACKGROUND

There is still uncertainty regarding ethnic differences in the prevalence, progression, and risk of coronary artery disease. Clues to possible racial differences in rates of coronary heart disease (CHD) may be found by identifying subclinical disease. Coronary artery calcification (CAC) can be used to predict risk of CHD in both symptomatic and asymptomatic subjects.

METHODS

Online databases were searched for studies assessing racial differences in CAC.

RESULTS

Most of the published studies have shown that racial differences exist in the prevalence and severity of CAC. Whites have a higher prevalence of CAC as compared to African Americans and other ethnic groups even after adjustment for risk factors. These differences in CAC are even more pronounced in men and in the elderly. Data regarding the distribution of CAC in ethnic groups outside the United States are limited. Emerging evidence indicates that while several ethnic groups outside the United States tend to have a greater prevalence of CHD risk factors, their prevalence of CAC is lower, as compared with Americans. Thus, the data obtained in the United States may not be able to be fully extrapolated to populations outside the United States for assessment of CHD risk.

CONCLUSIONS

The presence and extent of CAC varies among different racial groups within and outside the United States. The relationship between calcification and the incidence of CHD in these ethnic groups needs further exploration. Thus, it is important to develop ethnic specific CAC nomograms to more accurately determine the underlying CHD risk associated with CAC in these individuals. It will also be imperative to obtain outcome data and relate it to baseline levels of CAC to help us put in perspective the significance of racial differences in CAC and how they impact on cardiac risk prediction.

Differences in the clinical features and outcomes in African Americans and whites with myocardial infarction

PURPOSE

Less is known about the differences in clinical and angiographic features and the outcomes of African Americans with ST-elevation myocardial infarction compared with whites with ST-elevation myocardial infarction. Accordingly, the current study examines the relationship of African American race to patient-related clinical factors, angiographic findings, and clinical events.

METHODS

We evaluated data from 32419 patients with ST-elevation myocardial infarction who received fibrinolysis. The primary outcomes of interest were 30-day and 5-year mortality.

RESULTS

African Americans comprised 5.1% of the study population (1664/32419). Compared with white patients, black patients were younger, were more likely female, had a higher prevalence of coronary risk factors, and were more likely to have higher presenting heart rate, blood pressure, and Killip Class. Coronary angiography rates were similar in the two groups, but blacks were less likely to undergo coronary revascularization. The patency of the infarct-related artery after thrombolysis or mechanical reperfusion was higher in blacks, who were more likely to have no significant coronary artery disease and less likely to have disease in two or more vessels. In-hospital stroke (adjusted odds ratio 1.75, 95% confidence interval [CI] 1.19-2.59) and major bleeding (adjusted odds ratio 1.32, 95% CI 1.13-1.55) were higher among African Americans. Although no differences were observed in the 30-day mortality between the two groups, African Americans who survived to 30 days had higher 5-year mortality than whites (17% vs 12.5%, adjusted hazard ratio 1.63, 95% CI 1.41-1.90).

CONCLUSIONS

Although 30-day survival was similar between African Americans and whites with ST-elevation myocardial infarction, in-hospital stroke and bleeding and 5-year mortality among 30-day survivors were significantly higher among blacks despite their younger age.

Gender, ethnicity, and genes in cardiovascular disease. Part 2: implications for pharmacotherapy

Women are underrepresented in clinical trials. Lower doses of beta-blockers are required for Southeast Asians. ACE and ARB's are teratogenic in the second trimester. Torsades de Pointes is more common in women related to a longer QT-interval. Lower dose OCPs decrease the risk of MI, stroke and thrombosis. HRTs are not effective for CAD prevention.

Recent advances in peripheral angioplasty and stenting

Utilization of percutaneous interventions for arterial and venous occlusive lesions continue to increase. With the progression of the technology supporting these therapeutic measures, the results of these interventions may be expected to improve. In general, a comparison of techniques for revascularization demonstrates similar initial technical success rates for surgery and percutaneous transluminal angioplasty. Angioplasty is often associated with lower procedural morbidity and mortality rates. Conversely, surgery frequently provides greater long-term patency. Late failure of percutaneous therapies may often be treated successfully with reintervention, however. The continued accumulation of experience with PTA and stenting will ultimately define its role in the management of occlusive disease.

Femoropopliteal occlusive disease: diagnosis, indications for treatment, and results of interventional therapy

The relative role of percutaneous therapy versus bypass surgery for femoropopliteal occlusive disease (FPD) represents an area of great controversy in the field of vascular medicine. This controversy is complicated by the very dynamic therapeutic options that continue to be introduced, particularly on the endovascular side. The purpose of this review is to provide an overview of the current diagnostic modalities available to characterize the level and degree of vascular insufficiency and summarize the currently available endovascular therapeutic options with their clinical role and outcomes. Finally, future therapeutic advances that will soon be evaluated in clinical trials will be discussed.

Cardiovascular risk factors in ethnic minority women aged < or =30 years

Men and women of African and South Asian ancestry in the United States are increasingly recognized as being at greater risk for coronary heart disease (CHD) than Caucasians of European ancestry. Relatively little data on the genetic and lifestyle risk factors that predispose women to CHD in these ethnic minorities are available. We compared coronary risk factors in a volunteer sample of African-American, Asian Indian American, and Caucasian American women of college age. Life style, dietary, hemodynamic and anthropometric parameters, and laboratory data were sought from 70 subjects in each ethnic group. African-American women were found to have lower triglyceride levels and higher apolipoproten A-1, high-density lipoprotein (HDL), lipoprotein (a) (Lp(a)), fibrinogen, and fasting insulin levels. They also consumed more fat and cholesterol than their peers, had a higher percentage of body fat, body weight, and body mass indexes, and reported less physical activity than Caucasians. Asian Indian American women had higher Lp(a), HDL, and fibrinogen levels than Caucasian American women, and also reported less physical activity. Thus, young African- American and Asian Indian American women have several modifiable risk factors as well as some nontraditional lipid risk factors that warrant consideration for explaining the increased prevalence of CHD in these ethnic groups. The tendency toward peripheral insulin insensitivity and increased body fat in this age group of African-American women suggests diet and exercise may reduce the risk of subsequent CHD.

Premenopausal black women are uniquely at risk for coronary heart disease compared to white women

Premenopausal black women have a two to threefold greater rate of coronary heart disease than premenopausal white women. This study was designed to provide greater insight into the reasons for this difference which is currently unclear. Coronary heart disease risk factors were compared in 100 black and 100 white, healthy premenopausal women, ages 18-45 years, and of relatively advantaged socioeconomic status. Compared to white women, black women had a higher body mass index (32.0±9.2 vs. 29.0±9.4 kg/m2, p=0.021), and higher systolic (124±17 vs. 115±14 mm Hg, p<0.0001) and diastolic (79±14 vs. 75±11 mm Hg, p=0.048) blood pressures. The mean plasma lipoprotein(a) concentration was markedly higher in the black women (40.2±31.3 mg/dL) than in the white women (19.2±23.7 mg/dL, p<0.0001). The plasma total homocysteine level was also higher in the black women (8.80±3.38 vs. 7.81±2.58 mmol/L, p=0.013). The black women, however, had lower plasma triglyceride levels (0.91±0.46 vs. 1.22±0.60 mmol/L, p<0.0001) and a trend toward higher high-density lipoprotein cholesterol levels (1.37±0.34 vs. 1.29±0.31 mmol/L, p=0.064) than the white women. Plasma total and low-density lipoprotein cholesterol levels were similar. Black women consumed more saturated fat and cholesterol. Rates of cigarette smoking and alcohol intake were low and similar between the races. In summary, compared to white women, black women had a higher mean body mass index, higher blood pressures, higher lipoprotein(a) and plasma total homocysteine levels, and greater consumption of saturated fat and cholesterol. The differences in coronary risk factors between these two premenopausal groups may explain the higher incidence of coronary heart disease in black women. (c) 2000 by CHF, Inc.

A randomized trial confirming the efficacy of reduced dose recombinant tissue plasminogen activator in a Chinese myocardial infarction population and demonstrating superiority to usual dose urokinase: the TUCC trial

BACKGROUND

Reports from Japan suggest effective myocardial infarction (MI) treatment in Asian patients with much lower doses of tissue plasminogen activators (tPA) than used in European and American regimens. Because increasing doses of fibrinolytics lead to increased bleeding complications, identification of patients who respond to reduced doses is of importance. We conducted a trial in the People's Republic of China in which reduced-dose recombinant tPA was compared with the standard local therapy, urokinase.

METHODS

Four hundred patients with acute MI within 12 hours of symptom onset were to be randomized to an 8-mg bolus of recombinant tPA followed by a 42-mg 90-minute infusion or 1.5 million units of urokinase as a 30-minute infusion. Patients received aspirin and heparin and underwent angiography to determine infarct artery patency 90 minutes after the start of therapy.

RESULTS

The Data and Safety Monitoring Board recommended premature termination after 342 patients were recruited. Infarct artery patency (grade 2 or 3) occurred in 79% of patients receiving recombinant tPA and in 53% of patients receiving urokinase (P <.001); Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was 48% and 28%, respectively (P <.001). The higher-patency-rate recombinant tPA growth had better posttreatment left ventricular ejection fractions, 58.6% versus 54.7%, P <.01. Adverse events were infrequent and not significantly different in the 2 groups.

CONCLUSIONS

This study confirms that a substantially lower dose of recombinant tPA is effective in Asian patients compared with that required in Western patients even after consideration of body weight. Specific dose-response studies should be performed with fibrinolytic regimens to avoid overdosage with its attendant risks of excess bleeding.

Racial and ethnic differences in the use of cardiovascular procedures: findings from the California Cooperative Cardiovascular Project

OBJECTIVES

This study used data from the California Cooperative Cardiovascular Project to examine the use of invasive and noninvasive cardiovascular procedures among Whites, African Americans, and Hispanics.

METHODS

The use of catheterization, percutaneous transluminal coronary angioplasty (PTCA), coronary artery bypass graft (CABG) surgery, and several noninvasive tests among all patients 65 years or older with a confirmed acute myocardial infarction in nonfederal hospitals from 1994 to 1995 was studied.

RESULTS

African Americans (n = 527) were less likely than Whites (n = 9489) to have received catheterization (adjusted odds ratio [OR] = 0.62, 95% confidence interval [CI] = 0.50, 0.76), PTCA (OR = 0.64, 95% CI = 0.49, 0.85), or CABG surgery (OR = 0.42, 95% CI = 0.27, 0.64); somewhat more likely to have received a stress test or an echocardiogram; and equally likely to have received a multiple-gated acquisition scan. Hispanics (n = 689) also were less likely than Whites to have received catheterization (OR = 0.82, 95% CI = 0.68, 0.98) or PTCA (OR = 0.58, 95% CI = 0.45, 0.75).

CONCLUSIONS

African Americans were less likely than Whites to undergo costly invasive cardiovascular procedures. In addition, Hispanics were less likely than Whites to have received catheterization and PTCA.

Insights into the pathophysiology of atherosclerosis and prognosis of black Americans with acute coronary syndromes

BACKGROUND

Disparities in prognosis for black and white patients with coronary heart disease have been widely reported. For several reasons it is unclear to what extent biologic factors contribute to these differences.

METHODS

The current medical literature regarding the pathophysiologic characteristics of cardiovascular disease is reviewed with emphasis on how racially mediated biologic differences may affect the manifestation, treatment, and prognosis of patients with coronary heart disease, particularly patients with acute coronary syndromes.

RESULTS

Black patients with coronary heart disease have a higher prevalence of ischemic heart disease risk factors, including hypertension, left ventricular hypertrophy, diabetes, and tobacco use. Other factors related to atherosclerosis, vascular reactivity, and thrombolysis that quantitatively and functionally differ among racial groups are identified. Prospective, randomized trials comparing outcomes among patients with acute coronary syndromes have included only a fraction of the available black population, although they reveal a similar short-term mortality rate for black and white patients. Several factors, including enhanced fibrinolysis among black patients with acute myocardial infarction, may in part counterbalance better understood and more prevalent comorbidities to equalize short-term (30-day) survival. All-cause, long-term (1-year) mortality appears worse for black patients compared with white patients with similar cardiovascular risk profiles.

CONCLUSION

As racially mediated biologic differences between black and white patients become better understood, targeted interventions to prevent coronary heart disease and treat acute coronary syndromes in black patients can be developed.

Premenopausal black women have more risk factors for coronary heart disease than white women

Premenopausal black women have a 2- to 3-fold greater rate of coronary heart disease (CHD) than premenopausal white women. The purpose of this study was to provide greater insight into the reasons for this difference, which are currently unclear. We compared CHD risk factors in 99 black and 100 white, healthy premenopausal women, aged 18 to 45 years, and of relatively advantaged socioeconomic status. Compared with white women, black women had a higher body mass index (32.0 +/- 9.2 vs 29.0 +/- 9.4 kg/m2, p = 0.021), and higher systolic (124 +/- 17 vs 115 +/- 14 mm Hg, p <0.0001) and diastolic (79 +/- 14 vs 75 +/- 11 mm Hg, p = 0.048) blood pressures. The mean plasma lipoprotein(a) concentration was markedly higher in the black women (40.2 +/- 31.3 mg/dl) than in the white women (19.2 +/- 23.7 mg/dl, p <0.0001). The plasma total homocysteine level was also higher in the black women (8.80 +/- 3.38 vs 7.81 +/- 2.58 micromol/L, p = 0.013). The black women, however, had lower plasma triglyceride levels (0.91 +/- 0.46 vs 1.22 +/- 0.60 mmol/L, p <0.0001), and a trend toward higher high-density lipoprotein (HDL) cholesterol levels (1.37 +/- 0.34 vs 1.29 +/- 0.31 mmol/L, p = 0.064) than the white women. Plasma total and low-density lipoprotein (LDL) cholesterol levels were similar, despite a greater consumption of saturated fat and cholesterol by the black women. Rates of cigarette smoking and alcohol intake were low and similar between the races. In summary, premenopausal black women had a higher mean body mass index, blood pressure, lipoprotein(a), and plasma total homocysteine level, and a greater consumption of saturated fat and cholesterol than white women. These differences in coronary risk factors may place the black women in our study at increased risk for CHD compared with the white women.

Racial differences in coronary calcium prevalence among high-risk adults

A total of 1,461 asymptomatic high-risk adult subjects were studied with digital subtraction fluoroscopy and conventional cinefluoroscopy to detect coronary calcium. Ethnicity and risk factor data were recorded. No subject had a history or electrocardiographic evidence of prior myocardial infarction. The prevalence of coronary calcium by digital subtraction fluoroscopy was high (58%). Substantial ethnic differences in prevalence were noted: 36% of African American subjects, 60% of Caucasian subjects, and 60% of Asian American subjects had definite radiographic evidence of coronary calcium. The difference in prevalence between African American and other subjects was significant (p < 0.0001) by chi-square test for all 3 races. These differences persisted in the unsubtracted cinefluoroscopic images (p < 0.0001) and after controlling for age, gender, and other risk factors (p = 0.003). After 20 +/- 11 months of follow-up, African Americans had more coronary artery disease events (13%) than Caucasians (6%) or Asian Americans (5%) (p = 0.04). Thus, African Americans have a significantly lower prevalence of coronary calcium than do Caucasians or Asian Americans. Based on the follow-up results, these differences in prevalence are not explained by differences in coronary artery disease risk.

Comparative case fatality analysis of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial: variation by country beyond predictive profile. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

OBJECTIVES

This study was designed to examine the variation in mortality rates among countries participating in the International Tissue Plasminogen Activator/Streptokinase Mortality Trial.

BACKGROUND

Despite uniform inclusion and exclusion criteria and protocol in this trial, 30-day mortality rates (irrespective of treatment allocation) ranged from 4.2% to 14.8% among the participating countries.

METHODS

With use of the risk factors identified by a multi-variate logistic model, the total study group was classified into deciles on the basis of each patient's risk profile and individual probability of dying within 30 days. Expected mortality rates were then calculated and compared with actual mortality for each decile of the total study group, as well as for patients from each country.

RESULTS

Independent risk factors for mortality were older age (odds ratio 1.97 for each 10-year increment), systolic hypotension (blood pressure < 95 mm Hg) at entry (odds ratio 3.7), Killip class > 1 at entry (odds ratio 3.5), history of antecedent angina (odds ratio 1.23 to 1.49), history of diabetes mellitus (odds ratio 1.64), previous infarction (odds ratio 1.23) and history of never smoking (odds ratio 1.37). The overall mortality rate among the 1,612 patients in risk deciles 9 and 10 was 26%; for the 1,606 patients in deciles 1 and 2 it was 1.2%, with a sensitivity of 58.6% and a specificity of 83.7%. The logistic model closely predicted and explained the different mortality rates for most countries (the differences between expected and actual mortality were nonsignificant). However, in the total study group, the difference between the expected and actual mortality was significant (p < 0.001). This difference was mainly ascribed to the two countries with the highest and lowest mortality rates. When the patients from these two countries were excluded from the analysis, the overall difference became nonsignificant.

CONCLUSIONS

These findings suggest that the recognized risk factors associated with increased case fatality in acute myocardial infarction account only in part for mortality differences across or within populations.

Recombinant tissue plasminogen activator in acute myocardial infarction in the Chinese in Hong Kong

Eighty-nine consecutive Chinese patients (69 males, 20 females) with acute myocardial infarction treated by 100 mg recombinant tissue plasminogen activator (7 intracoronarily, 82 intravenously) at 3.7 +/- 1.0 h after onset, and intravenous heparin or dipyridamole therapy started at 3 h, were studied prospectively. Their mean age was 59.6 +/- 10.6 yr. Forty-six patients (51.7%) had anterior and 39 patients (43.8%) had inferior infarcts. Clinical evidence of reperfusion were seen in 63 patients (70.8%), while new complications included hypotension (5.6%), heart failure (6.7%), cardiac arrhythmias (76.4%) majority of which are related to reperfusion and self-remitting, haematoma around vascular access sites (23.6%), melaena (3.3%) and cerebral infarction (2.2%). Maximal changes in coagulation profiles were seen at 3 h, including a decrease in fibrinogen by 64.2% and an increase in fibrin degradation products by 47 times. The changes in haemostatic variables were not related to body weight or bleeding complications. Nine patients (10.1%) had recurrence of angina and 6 patients (6.9%) died due to pump failure and reinfarction. Angiogram at 14 days confirmed TIMI 2 or 3 patency of infarct-related arteries in 63 out of 73 (86.3%) patients, with a mean global ejection fraction of 52.5 +/- 12.4%. Nearly all survivors could maintain class I-II functional status after discharge. The safety and promise of recombinant tissue plasminogen activator for acute myocardial infarction in the Chinese were confirmed.

Thrombolytic therapy in cerebrovascular disorders

The knowledge obtained from the ongoing investigational trials of tPA for acute ischemic stroke will not only help establish the appropriate dose range and complication rates but will also further develop the clearly mandatory rapid, aggressive team approach needed to truly treat acute ischemic strokes successfully. Experimental cerebral ischemia data have pointed to the need to treat acute clinical stroke within only a few hours or less to effectively reduce stroke morbidity and mortality. Specifically, with reversible MCA occlusion models of focal cerebral ischemia (dogs and cats), the animals uniformly survive without neurological deficit if the occlusion is for less than 2 to 3 hours. Similarly in primates, MCA occlusion for 3 hours or less will lead to clinical improvement and a decrease in infarct size, with complete recovery generally associated with less than 2 hours of MCA occlusion. Therefore, it appears unlikely that ischemic brain can be salvaged if vascular occlusion persists longer than 4 to 6 hours (similar to the pathophysiology of myocardial ischemia). Further, at least one third of ischemic stroke patients reperfuse spontaneously (and obviously too late) within 48 hours of stroke onset. Several factors believed to be related to successful outcome after thrombolytic therapy are summarized in Table 16. A schematic approach to determining the response to thrombolytic agents in acute ischemic stroke is outlined in Table 17. Zivin succinctly reviews thrombolysis for stroke, both experimental and clinical, and summarizes some of the difficulties of the early clinical stroke trials with thrombolytic agents and speculates about future prospects. He believes tPA may prove valuable in the treatment of some forms of thromboembolic stroke. Its usefulness may depend in part on how quickly the drug can be initiated and the risk of side effects; factors that will require further study. The currently used doses of tPA may be too low to lyse large cerebral arterial clots and, therefore, if current trials do not show a positive treatment response, further trials with higher doses may be indicated. The implications of a potentially effective treatment for truly acute stroke are enormous: stroke will need to be considered by all (lay public through to caregivers) as a true medical emergency, analogous to MI and trauma.(ABSTRACT TRUNCATED AT 400 WORDS)