Impact of in-hospital acquired thrombocytopenia in patients undergoing primary angioplasty for acute myocardial infarction

A systematic review and meta-analysis of impact of baseline thrombocytopenia on cardiovascular outcomes and mortality in patients undergoing percutaneous coronary intervention

BACKGROUND

Thrombocytopenia (TP) is associated with higher incidence of bleeding in the setting of percutaneous coronary intervention (PCI) leading to increased morbidity and mortality. Herein, we report a meta-analysis evaluating the effects of baseline thrombocytopenia (bTP) on cardiovascular outcomes in patients undergoing PCI.

METHODS

Literature search was performed using PubMed, Embase, Cochrane library and clinicaltrials.gov from inception till October 2019. Patients were divided into two groups: Patients with (a) no Thrombocytopenia (nTP) (b) bTP before PCI. Primary endpoints were in-hospital, and all-cause mortality rates at the longest follow-up. The main summary estimate was random effects risk ratio (RR) with 95% confidence intervals (CIs).

RESULTS

A total of 6,51,543 patients from 10 retrospective studies were included. There was increased in-hospital all-cause mortality (RR 2.58 [1.7-3.8], p < .001) and bleeding (RR 2.37 [1.41-3.98], p < .005), in the bTP group compared to the nTP group. There was no difference for in-hopsital major adverse cardiovascular outcomes (MACE) (RR 1.38 [0.94-2.0], p < .10), post-PCI MI (RR 1.17 [0.9-1.5], p = .19) and TVR (RR 1.65 [0.8-3.6], p = .21), respectively. Outcomes at longest follow-up showed increased incidence of all-cause mortality (RR 1.86 [1.2-2.9], p < .006) and bleeding (RR 1.72 [1.1-2.9], p = .04) in bTP group, while there was no significant difference for post-PCI MI (RR 1.07 [0.91-1.3], p = .42), MACE (RR 1.86 [0.69-1.8], p = .68) and TVR (RR 1.1 [0.9-1.2], p = .93) between both groups.

CONCLUSIONS

bTP in patients undergoing PCI is associated with increased mortality and predicts risk of bleeding.

Risk factors and prognostic impact of post-discharge bleeding after endovascular therapy for peripheral artery disease

This study evaluated the incidence, predictors, and impact of bleeding requiring hospitalization following successful endovascular therapy (EVT) for peripheral artery disease. Platelet inhibition after EVT reduces the risk of major adverse limb events but increases the risk of bleeding. The incidence of post-discharge bleeding after EVT, its independent predictors, and its prognostic importance in clinical practice have not been fully addressed. We evaluated 779 consecutive patients who underwent EVT. We found that 77 patients (9.9%) were hospitalized for major bleeding during follow-up after EVT (median 39 months, range 22-66 months), with almost half (48.1%) of the bleeding categorized as gastrointestinal bleeding. Significant predictors of post-discharge bleeding were hemodialysis (hazard ratio (HR), 3.12; 95% CI: 1.93 to 5.05; p < 0.001) and dual antiplatelet therapy (DAPT) use (HR, 1.87; 95% CI: 1.03 to 3.41; p = 0.041). During follow-up, the all-cause mortality-free survival rate was significantly worse in patients who had experienced major bleeding than in those who had not (log-rank test χ² = 54.6; p < 0.001). Cox proportional hazards analysis showed that major bleeding (HR, 2.78; 95% CI: 1.90 to 4.06; p < 0.001) was an independent predictor of all-cause death after EVT. Hospitalization for post-discharge bleeding after EVT is associated with a substantially increased risk of death, even after successful EVT. We concluded that patients' predicted bleeding risk should be considered when selecting patients likely to benefit from EVT, and that the risk should be considered especially thoroughly in hemodialysis patients.

Study of the Functional State of the Proximal Renal Tubules in Patients with Asymptomatic Chronic Heart Failure in Dyslipidemia and its Correction with Simvastatin Treatment

Aim. To study indicators of epithelial dysfunction in the proximal renal tubules by determining the activity of organ-specific enzymes neutral α-glucosidase (NAG) and L-alanine aminopeptidase (LAAP), in patients with the initial stage of chronic heart failure in dyslipidemia, and the possibility of reducing with simvastatin.Material and methods. The study involved 90 subjects, who were divided into control and main groups. The control group consisted of 30 practically healthy individuals, the main group was divided into 2 subgroups: patients with stage I chronic heart failure (CHF) without type 2 diabetes mellitus (DM2) and patients with CHF with DM2. Patients of each of the main subgroups received simvastatin 20-40 mg/day in addition to treatment of the main pathology. The main group included patients with a total serum cholesterol level of more than 6.0 mmol/l, a BMI level of more than 30 kg/m2, and who had not previously taken statins. The exclusion criterion was a violation of the filtration capacity of the kidneys and the presence of gross dysfunction of organs and systems of the body. The functional state of the proximal renal tubules was assessed by the concentration of NAG and LAAP in dialized urine.Results. Initially, the level of activity of renal enzymes in representatives of both major subgroups is higher than the group of practically healthy individuals. Taking simvastatin in the CHF without DM2 subgroup does not cause an increase in enzyme activity throughout the entire observation period, either at a daily dosage of 20 mg (NAG - 12.36±2.65 ncat/1 14.1±5.23 ncat/1 and after 3 and 6 months, LAAP - 9.4±1.62 and 11.2±2.99 ncat/1 after 3 and 6 months), or at a dosage of 40 mg/day (NAG - 30.47±3.85 and 26.2±6.75 ncat/1 after 3 and 6 months; LAAP -17.3±3.56 and 19.58±3.83 ncat/1 after 3 and 6 months). Taking simvastatin 20 mg/day in patients with CHF with DM 2 causes an increase in the NAG activity: 26.68±6.03 and 34.57±9.73 ncat/1 after 3 and 6 months). Taking simvastatin 40 mg/day increase both enzyme activity: NAG -34.3±8.7 and 46.94±9.02 ncat/1 after 3 and 6 months, LAAP - 17.08±5.81 and 22.41±4.89 ncat/1 after 3 and 6 months).Conclusion. The appointment of simvastatin in patients with dyslipidemia on the background of obesity is permissible in order to normalize lipid metabolism. Safe for the functional state of the proximal renal tubules, long-term administration of simvastatin, within the limits of medium-therapeutic dosages, is possible for patients without type 2 diabetes. Long-term use of simvastatin in patients with dyslipidemia on the background of type 2 diabetes mellitus has a negative effect on the epithelium of the proximal renal tubules, in the form of an increase in the activity of renal organ-specific enzymes, which indicates an increased dystrophy of the epithelium.

Impact of Acquired Thrombocytopenia on Cardiovascular Outcomes in Patients With Coronary Artery Disease Undergoing Percutaneous Coronary Intervention: A Systematic Review and Meta-Analysis

BACKGROUND

Acquired thrombocytopenia (aTP) is associated with a high frequency of bleeding and ischemic complications in patients undergoing percutaneous coronary intervention (PCI). Herein, we report a meta-analysis evaluating the adverse effects of aTP on cardiovascular outcomes and mortality post-PCI.

METHODS

A literature search was performed using PubMed, Embase, Cochrane and, clinicaltrials.gov from the inception of these databases through October 2019. Patients were divided into two groups: 1) No Thrombocytopenia (nTP) and 2) Acquired Thrombocytopenia (aTP) after PCI. Primary endpoints were in-hospital, 30-day and all-cause mortality rates at the longest follow-up. The main summary estimate was random effects Risk ratio (RR) with 95% confidence intervals (CIs).

RESULTS

Seven studies involving 57,247 participants were included. There was significantly increased in-hospital all-cause mortality (HR 10.73 [6.82-16.88]), MACE (HR 2.96 [2.24-3.94]), major bleeding (HR 4.78 [3.54-6.47]), and target vessel revascularization (TVR) (HR 7.53 [2.8-20.2]), in the aTP group compared to the nTP group. Similarly, aTP group had a statistically significant increased incidence of 30-day all-cause mortality (HR 6.08), MACE (HR 2.77), post-PCI MI (HR 1.98), TVR (HR 5.2), and major bleeding (HR 12.73). Outcomes at longest follow-up showed increased incidence of all-cause mortality (HR 3.98 [1.53-10.33]) and MACE (HR 1.24 [0.99-1.54]) in aTP group, while there was no significant difference for post-PCI MI (HR 0.94 [0.37-2.39]) and TVR (HR 0.96 [0.69-1.32]) between both groups.

CONCLUSIONS

Acquired Thrombocytopenia after PCI is associated with increased morbidity, mortality, adverse bleeding events and the need for in-hospital and 30-day TVR.

Platelet count as a new biomarker for acute kidney injury induced by hemorrhagic shock

The aim of this study was to investigate the association between nadir platelet count and acute kidney injury (AKI) or 28-day all-cause mortality induced by hemorrhagic shock (HS), and to determine the cutoff value of nadir platelet count in HS clinical practice. This retrospective study included hospitalized patients enrolled in a tertiary-care teaching hospital from January 1, 2010 to December 31, 2015. Clinical data from HS admitted to the intensive care unit (ICU) were evaluated. Nadir platelet count was defined as the lowest values in the first 48 h. Multivariate logistic regression and Cox proportional hazards regression were used to assess the correlation between nadir platelet count and AKI or 28-day all-cause mortality induced by HS, respectively; the area under receiver operating characteristic (AU-ROC) and Youde's index were used to determine the optimal cutoff value of nadir platelet count. Kaplan-Meier's method and log-rank test were assessed for the 28-day all-cause mortality in AKI and non-AKI groups. Of 1589 patients screened, 84 patients (mean age,37.1 years; 58 males) were included in the primary analysis in which 30 patients with AKI. Multiple logistic results indicated that nadir platelet count was a risk factor of AKI (OR = 0.71,95% confidence interval [CI] 0.54-0.93, P < 0.05). Cox regression analysis revealed that nadir platelet count was independent risk factors for 28-day all-cause mortality (Hazard ratios [HR]0.89,95%CI 0.76-0.99, P < 0.05). Kaplan-Meier curve showed that 28-day all-cause mortality was significantly higher in patients with AKI than non-AKI (P < 0.001).These results suggest that nadir platelet count in the first 48 h is a new biomarker for AKI and 28-day all-cause mortality induced by HS. Moreover, the risk for AKI and 28-day all-cause mortality in HS patients decreased by 29% and 11%, respectively, for every 10 × 10⁹/L increase in platelet count. Additional studies are needed to investigate whether elevation of nadir platelet count reduces the risk in different genders.

Statin Use and Gastrointestinal Hemorrhage: A Large Retrospective Cohort Study

BACKGROUND

Nearly 70% of Americans with cardiovascular disease use statins, which have documented bleeding effects independent of their cholesterol-lowering activities. However, the literature is conflicting regarding the association between statin use and gastrointestinal hemorrhage.

OBJECTIVES

The aim of this study was to investigate the risk of gastrointestinal hemorrhage in statin users.

METHODS

In this retrospective cohort study, data from the Truven Health MarketScan^® Research Database (2009-2015) were used to investigate the risk of gastrointestinal hemorrhage amongst statin users aged 30-65 years at the initial prescription claim. Statin users and a group of negative controls (i.e. other chronic medication users) were followed until first gastrointestinal hemorrhage event (both inpatient and outpatient, as well as restricted to inpatient), and were censored at treatment discontinuation, disenrollment from coverage, or the end of the study period.

RESULTS

Statin users had an elevated risk of gastrointestinal hemorrhage, which was especially apparent in the first year of treatment (1-year adjusted hazard ratio 1.19; 95% confidence interval (CI) 1.15-1.23). The risk of gastrointestinal hemorrhage leading to hospitalization was even higher (1-year adjusted hazard ratio 1.38; 95% CI 1.30-1.69). High-intensity statin users had a greater rate of gastrointestinal hemorrhage than moderate-intensity users (incidence rates per 1000 subject-years 22.2 (95% CI 21.9-22.8) vs. 21.5 (95% CI 21.3-21.8), respectively).

CONCLUSIONS

In a population of commercially insured subjects aged 30-65 years, statin users had a higher risk for gastrointestinal hemorrhage than other chronic medication users. These findings are important when treating patients at a high risk for bleeding events.

Bivalirudin versus heparin in patients undergoing percutaneous peripheral interventions: A systematic review and meta-analysis

Background

Bivalirudin may be an effective alternative anticoagulant to heparin for use in percutaneous peripheral interventions. We aimed to compare the safety and efficacy of bivalirudin versus heparin as the procedural anticoagulant agent in patients undergoing percutaneous peripheral intervention.

Methods

For this meta-analysis and systematic review, we conducted a search in PubMed, Medline, Embase, and Cochrane for all the clinical studies in which bivalirudin was compared to heparin as the procedural anticoagulant in percutaneous peripheral interventions. Outcomes studied included all-cause mortality, all-bleeding, major and minor bleeding, and access site complications.

Results

Eleven studies were included in the analysis, totaling 20,137 patients. There was a significant difference favoring bivalirudin over heparin for all-cause mortality (risk ratio 0.58, 95% CI 0.39–0.87), all-bleeding (risk ratio 0.62, 95% CI 0.50–0.78), major bleeding (risk ratio 0.61, 95% CI 0.39–0.96), minor bleeding (risk ratio 0.66, 95% CI 0.47–0.92), and access site complications (risk ratio 0.66, 95% CI 0.51–0.84). There was no significant difference in peri-procedural need for blood transfusions (risk ratio 0.79, 95% CI 0.57–1.08), myocardial infarction (risk ratio 0.87, 95% CI 0.59–1.28), stroke (risk ratio 0.77, 95% CI 0.59–1.01), intracranial bleeding (risk ratio 0.77, 95% CI 0.29–2.02), or amputations (OR 0.75, 95% CI 0.53–1.05).

Conclusion

Our meta-analysis suggests that bivalirudin use for percutaneous peripheral interventions is associated with lower all-cause mortality, bleeding, and access site complications as compared to heparin. Further large randomized trials are needed to confirm the current results.

Clinical importance of thrombocytopenia in patients with acute coronary syndromes: a systematic review and meta-analysis

Thrombocytopenia (TP) is common in hospitalized patients. In the context of acute coronary syndromes (ACS), TP has been linked to adverse clinical outcomes. We present a systematic review and meta-analysis of the evidence on the clinical importance of preexisting and in-hospital acquired TP in the context of ACS. Specifically, we address (a) the prevalence and associated factors with TP in the context of ACS; and (b) the association between TP and all-cause mortality, major adverse cardiovascular events (MACEs), and major bleeding. We conducted systematic literature searches in MEDLINE and Web of Science. For the meta-analysis, we fit linear mixed models with a random study-specific intercept for the aggregate outcomes. A total of 16 studies and 190 915 patients were included in this study. Of these patients, 8.8% ± 1.2% presented with preexisting TP while 5.8% ± 1.0% developed TP after hospital admission. Preexisting TP was not statistically significantly associated with adverse outcomes. Acquired TP was associated with greater risk of all-cause mortality (risk difference [RD]: 4.3%; 95% confidence interval [CI]: 2-6%; p = 0.04), MACE (RD: 8.5%; 95% CI: 1-16.0%; p = 0.037), and major bleeding (RD: 11.9%; 95% CI: 5-19%; p = 0.005). In conclusion, TP is a prevalent condition in patients admitted for an ACS and identifies a high-risk patient population more likely to experience ischemic and bleeding complications, as well as higher mortality.

Etiology and complications of thrombocytopenia in hospitalized medical patients

To determine incidence, risk factors, hematologic complications, and prognostic significance of thrombocytopenia in the general medicine population, we performed a single-institutional, retrospective study of all adult patients admitted to a general medical ward from January 1st, 2014 to December 31st, 2014 with hospital-acquired thrombocytopenia. Those with moderate thrombocytopenia, defined as a platelet count nadir of <100 × 10^9/L and/or a >50% relative decline, were compared to those with less severe thrombocytopenia. Of the 7420 patients admitted, 465 (6.3%) developed hospital-acquired thrombocytopenia. Infection and moderate thrombocytopenia were present in 56 and 23%, respectively. Severe sepsis and antibiotic use were both associated with moderate thrombocytopenia, and proton pump inhibitor use was statistically significant in both univariate and multivariate analysis. Hematologic complications were more frequent with moderate thrombocytopenia, including frequency of HIT testing and red blood cell transfusions. Outcome metrics including transfer to an intensive care unit (OR 6.78), death during admission (OR 6.85), and length of stay (10.6 vs. 5.1 days) were all associated with moderate thrombocytopenia. Thrombocytopenia is associated with poor prognosis, and the association between moderate thrombocytopenia and proton pump inhibitor use is relatively novel and should be validated in prospective studies.

Thrombocytopenia on the first day of emergency department visit predicts higher risk of acute kidney injury among elderly patients

Background

Few studies have addressed risk factors for acute kidney injury (AKI) in geriatric patients. We investigated whether thrombocytopenia was a risk factor for AKI in geriatric patients with medical illnesses.

Methods

A prospective cohort study was conducted, by recruiting elderly (≥65 years) patients who visited the emergency department (ED) for medical illnesses during 2014. They all received hemogram for platelet count determination, and were stratified according to the presence of thrombocytopenia (platelets, <150 K/μL) during their initial ED evaluation. They were prospectively followed up during their ED stay. We analyzed the relationship between the diagnosis of thrombocytopenia and subsequent AKI after ED stay, using Cox proportional hazard modeling, with platelet count as a continuous variable or thrombocytopenia as a categorical variable.

Results

Of 136 elderly patients (mean age of 80.7 ± 8.2 years, 40% with chronic kidney disease, and 39% with diabetes) enrolled, 22.8% presented with thrombocytopenia, without differences in baseline renal function. After a mean ED stay of 4.4 ± 2.1 days, 41.9% developed AKI (52.6% Kidney Disease Improving Global Outcomes [KDIGO] grade 1, 24.6% grade 2, and 22.8% grade 3). Patients with higher AKI severity had stepwise lower platelet counts compared to those without AKI. The Cox proportional hazard model revealed that lower platelet count as a continuous variable (hazard ratio [HR] 0.984, 95% confidence interval [CI] 0.975–0.994) and as a categorical variable (presence of thrombocytopenia) (HR 1.86, 95% CI 1.06–3.27) increased the risk of AKI. The sensitivity analyses accounting for nephrotoxic medications use, including non-steroidal anti-inflammatory drugs, vancomycin, and contrast, yielded similar results.

Discussion

Thrombocytopenia is common among ED-visiting elderly, and the potential relationship between platelet counts and the risk of AKI suggests the utility of checking hemogram for those at-risk ofdeveloping adverse renal events.

Conclusion

Thrombocytopenia on initial presentation might indicate an increased risk of AKI among elderly patients with medical illnesses.

The effect of in-hospital acquired thrombocytopenia on the outcome of patients with acute coronary syndromes: A systematic review and meta-analysis

BACKGROUND

In-hospital acquired thrombocytopenia (TP) is relatively common among patients hospitalized with acute coronary syndromes (ACS). However, its effect on short-term and long-term outcomes has yet to be reviewed systematically.

METHODS

We conducted a systematic review and meta-analysis of clinical studies assessing the relationship between new-onset in-hospital TP and adverse outcomes among ACS patients. MEDLINE, Scopus and the Cochrane Library were searched for eligible studies published before March 20, 2016.

RESULTS

Ten studies reporting on a total of 142,161 ACS patients were identified. 8133 patients showed evidence of new-onset TP during the course of their hospitalization. Compared with patients with normal platelet counts, patients with new-onset TP had a prolonged in-hospital stay, significantly higher risk of both short-term mortality (<30days) (Odds ratio (OR) [95% confidence interval (CI)]: 5.58 [3.63-8.57]) and late death (6months to 1year) (OR [95% CI]: 3.45 [2.35-5.07]), as well as a significantly higher risk of major bleeding events in the first 30days (OR [95% CI]: 6.93 [5.13-9.38]). In addition, risk for other secondary cardiovascular endpoints, including recurrent myocardial infarction, stroke, in-hospital heart failure, stent thrombosis and unplanned revascularization was also significantly higher in the TP versus the no TP group.

CONCLUSIONS

Development of TP during the in-hospital management of ACS patients is a significant predictor of both short- and long-term adverse events, including mortality. In the light of this evidence, clinicians should be cautious and closely monitor abnormal platelet counts that present early following an ACS.

The role of Glycoprotein IIb/IIIa inhibitors in acute coronary syndromes and the interference with anemia

The role played by glycoprotein (GP) IIb/IIIa inhibitors (GPI) has continuously evolved until the most recent Guidelines whereby they were stepped down from class I to class II recommendation for treating acute coronary syndromes (ACS). GPI compete with a wider use of ADP inhibitors and novel anticoagulant drugs although GPI use has greatly narrowed. However, GPI may still have a role. Several criteria were proposed to define post-PCI anemia which is strictly related to bleeding and transfusion. In ACS, it should be important to define anemia in comparative terms versus baseline levels: ≥ 15% of red blood cell decrease should be a practical cut-off value. If one wishes to concentrate on hemoglobin (Hb), a≥2g/dl Hb decrease from baseline should be considered. It is important to recognize post-PCI anemia in the setting of ACS. There are sub-populations exposed to short-term hemorrhagic and/or long-term ischemic risks. Ischemic and hemorrhagic risks need to be carefully evaluated along with thrombocytopenia and its prognostic significance in order to put all these blood and rheological parameters into a clinically oriented perspective on which therapeutical decisions should be based. Definition of high risk procedures (complexity, angiographic characteristics and patient's risk profile, regardless whether STEMI or NSTEMI) may help selecting GPI. There are positive elements in GPI use: efficacy, rapid onset and reversibility of action, absence of pharmacogenomic variability, pharmacoeconomic considerations and the possibility of intracoronary administration. All these elements should be evaluated when selecting these agents for therapeutics.

SCAI Expert consensus statement: Evaluation, management, and special considerations of cardio-oncology patients in the cardiac catheterization laboratory (endorsed by the cardiological society of india, and sociedad Latino Americana de Cardiologıa intervencionista)

In the United States alone, there are currently approximately 14.5 million cancer survivors, and this number is expected to increase to 20 million by 2020. Cancer therapies can cause significant injury to the vasculature, resulting in angina, acute coronary syndromes (ACS), stroke, critical limb ischemia, arrhythmias, and heart failure, independently from the direct myocardial or pericardial damage from the malignancy itself. Consequently, the need for invasive evaluation and management in the cardiac catheterization laboratory (CCL) for such patients has been increasing. In recognition of the need for a document on special considerations for cancer patients in the CCL, the Society for Cardiovascular Angiography and Interventions (SCAI) commissioned a consensus group to provide recommendations based on the published medical literature and on the expertise of operators with accumulated experience in the cardiac catheterization of cancer patients.

Efficacy and safety of fondaparinux versus enoxaparin in patients undergoing percutaneous coronary intervention treated with the glycoprotein IIb/IIIa inhibitor tirofiban

BACKGROUND

In worldwide, the mortality rate of acute myocardial infarction (AMI) raises year by year. Although the applications of percutaneous coronary intervention (PCI) and anticoagulants effectively reduce the mortality of patients with acute coronary syndrome (ACS), but also increase the incidence of bleeding. Therefore, drugs with stable anticoagulant effects are urgently required.

METHODS

We enrolled 894 patients with acute coronary syndrome who underwent percutaneous coronary intervention in Shenyang Northern Hospital from February 2010 to May 2012; 430 patients were included in the fondaparinux group (2.5 mg/d), and 464 were included in the enoxaparin group (1 mg/kg twice daily). Fondaparinux and enoxaparin were applied for 3-7 days. All patients were treated with tirofiban (10 μg/kg for 3 min initially and 0.15 μg/(kg · min) for 1 to 3 days thereafter). The primary efficacy endpoint was the incidence of a major adverse cerebrovascular or cardiovascular event. The primary safety endpoint was bleeding within 30 days and 1 year after percutaneous coronary intervention.

RESULTS

One-year data were available for 422 patients in the fondaparinux group and for 453 in the enoxaparin group. The incidence of a major adverse cerebrovascular or cardiovascular event (10.9 % vs 12.6 %, P = 0.433) and cardiac mortality (0.5 % vs 1.5 %, P = 0.116) were generally lower in the fondaparinux group than in the enoxaparin group, although the differences were not significant. Compared with the enoxaparin group, the fondaparinux group had a significantly decreased rate of bleeding at 30 days (0.9 % vs 2.8 %) and 1 year (2.4 % vs 5.4 %). In addition, the rate of major bleeding events was lower in the fondaparinux group, but this difference was not significant (0.2 % vs 0.9 %, 0.2 % vs 1.1 %).

CONCLUSIONS

In tirofiban-treated patients with acute coronary syndrome undergoing percutaneous coronary intervention, fondaparinux presented similar efficacy for ischemia events as enoxaparin. However, fondaparinux significantly decreased the incidence of bleeding, thus providing safer anticoagulation therapy.

Antiplatelet drugs in patients with enhanced platelet turnover: biomarkers versus platelet function testing

Platelets are key players in atherothrombosis. Antiplatelet therapy comprising aspirin alone or with P2Y12-inhibitors are effective for prevention of atherothrombotic complications. However, there is interindividual variability in the response to antiplatelet drugs, leaving some patients at increased risk of recurrent atherothrombotic events. Several risk factors associated with high on-treatment platelet reactivity (HTPR), including elevated platelet turnover, have been identified. Platelet turnover is adequately estimated from the fraction of reticulated platelets. Reticulated platelets are young platelets, characterised by residual messenger RNA. They are larger, haemostatically more active and there is evidence that platelet turnover is a causal and prognostic factor in atherothrombotic disease. Whether platelet turnover per se represents a key factor in pathogenesis, progression and prognosis of atherothrombotic diseases (with focus on acute coronary syndromes) or whether it merely facilitates insufficient platelet inhibition will be discussed in this state-of-the art review.

Postprocedural anticoagulation for specific therapeutic indications after revascularization for ST-segment elevation myocardial infarction (from the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction Trial)

Postprocedural anticoagulation (AC) after primary percutaneous coronary intervention (PCI) in ST-segment elevation myocardial infarction (STEMI) may be administered for a number of specific therapeutic indications (e.g. atrial fibrillation or left ventricular thrombus). However, the safety and effectiveness of such post-PCI AC for specific indications are not well defined. Thus, we sought to study outcomes after postprocedural AC for specific indications in patients undergoing primary PCI for STEMI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial. Patients who underwent primary PCI for STEMI in the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction trial were grouped according to whether they received specific indication AC. Adverse outcomes were assessed using propensity-adjusted multivariate analyses. After excluding patients who received post-PCI AC solely for routine prophylaxis, 410 patients (16.6%) received postprocedural AC for specific indications and 2,063 patients (83.4%) received no post-PCI AC. After propensity adjustment, use of postprocedural AC for specific indications was associated with higher rates of cardiac mortality, reinfarction, stent thrombosis, and major bleeding at 30 days compared with patients who received no AC post-PCI. In conclusion, in this large prospective study, use of postprocedural AC for specific indications after primary PCI for STEMI was independently associated with early rates of adverse ischemic and hemorrhagic outcomes. Post-PCI AC for specific indications was also associated with worse outcomes from 30 days to 3 years. Further studies are warranted to determine the optimal use of postprocedural AC after primary PCI in STEMI.

Hospital-acquired thrombocytopenia

The development of thrombocytopenia is common in hospitalized patients and is associated with increased mortality. Frequent and important causes of thrombocytopenia in hospitalized patients include etiologies related to the underlying illness for which the patient is admitted, such as infection and disseminated intravascular coagulation, and iatrogenic etiologies such as drug-induced immune thrombocytopenia, heparin-induced thrombocytopenia, posttransfusion purpura, hemodilution, major surgery, and extracorporeal circuitry. This review presents a brief discussion of the pathophysiology, distinguishing clinical features, and management of these etiologies, and provides a diagnostic approach to hospital-acquired thrombocytopenia that considers the timing and severity of the platelet count fall, the presence of hemorrhage or thrombosis, the clinical context, and the peripheral blood smear. This approach may offer guidance to clinicians in distinguishing among the various causes of hospital-acquired thrombocytopenia and providing management appropriate to the etiology.

Long-term outcomes associated with hospital acquired thrombocytopenia among patients with non-ST-segment elevation acute coronary syndrome

BACKGROUND

Acquired thrombocytopenia after a non-ST-segment-elevation-acute coronary syndrome (NSTE-ACS) has been associated with increased in-hospital mortality and hemorrhagic complications, but longer term outcomes are unclear. We examined the association between thrombocytopenia and long-term outcomes after accounting for thrombocytopenia severity and discharge medication use.

METHODS

Data from 7,435 NSTE-ACS patients enrolled in the SYNERGY trial were analyzed. Severe thrombocytopenia was defined as a nadir platelet count <100 × 10(9)/L or a ≥ 50% drop from baseline. Mild thrombocytopenia was defined as a nadir platelet count between 100 and 149 × 10(9)/L with a <50% drop from baseline. The primary outcomes of interest were in-hospital GUSTO moderate-severe bleeding and 1-year mortality.

RESULTS

Overall, 675 patients (9.1%) developed mild thrombocytopenia and 139 patients (1.9%) developed severe thrombocytopenia. In-hospital bleeding risks were higher in patients with mild (7.7%, adjusted HR 1.63, 95% CI 1.16-2.29) or severe (28.2%, adjusted HR 6.93, 95% CI 4.55-10.56) thrombocytopenia than in patients without thrombocytopenia (5.2%). One-year mortality rates were 6.5%, 8.1%, and 28.1% among patients with no, mild, and severe thrombocytopenia, respectively (log rank P < 0.001) but only severe thrombocytopenia remained significantly associated with increased mortality after adjustment: HR 4.07, 95% CI 2.86-5.78. Patients who developed severe thrombocytopenia were less likely to be discharged on guideline-recommended antiplatelet therapy. The relationship between severe thrombocytopenia and mortality was attenuated by but persisted after adjusting for discharge medication use (HR 2.83, 95% CI 1.49-5.38).

CONCLUSIONS

Thrombocytopenia occurs commonly during the course of NSTE-ACS care; even mild decreases are associated with clinically meaningful bleeding. Patients who developed severe thrombocytopenia were less likely to be discharged on guideline-recommended antiplatelet therapy; this may contribute to their higher associated long-term mortality.

Prognostic significance of post percutaneous coronary intervention thrombocytopenia

Several definitions of post percutaneous coronary intervention (PCI) thrombocytopenia (TC) were formulated. Recent studies demonstrated that a relative drop in platelet count ≥ 25% is the most appropriate criterion. By this definition a population is detected that is exposed not only to increased risk of hemorrhagic complications but also to increased risk of ischemic events, which may appear a paradox. In patients with acute coronary syndromes undergoing PCI, several conditions might be associated with TC: cardiopulmonary by-pass and the presence of extra corporeal membrane oxygenators, intra aortic balloon pump (IABP), cardiogenic shock, thrombolytic drugs and anticoagulant or antiplatelet drugs. Several studies demonstrated that TC and ischemic outcomes are related although it is unclear whether this is a direct relationship or TC is just a secondary effect of another cryptic protagonist. It is suggested that further investigations determine whether there is a real link between TC, a probably well defined covariate, and ischemic outcomes or whether IABP is the joining link between these two variables and whose presence needs in any case be considered in multivariable statistics. Post-PCI TC could be only a secondary effect of IABP use. On turn, the prolonged use of heparin necessarily accompanying the use of IABP, and producing a paradoxical pro-thrombotic TC, might also be implicated.

Reprint of "Decline in platelet count and long-term post-PCI ischemic events: implication of the intra-aortic balloon pump"

AIMS

Thrombocytopenia (TC) following a percutaneous coronary intervention (PCI) has been associated not only with hemorrhagic, but also with ischemic outcomes. The purpose of this study was to re-examine the relationship of TC with ischemic events at a 1-year follow-up, and investigate the possible associations.

METHODS AND RESULTS

We studied a real-world, unselected population of ischemic patients undergoing PCI, totaling 861 patients-year, and divided into two groups: with TC (delta platelet count ≥25% from baseline to post-PCI during the hospital admission) and without TC. Compared with patients without TC, patients with TC had a higher and earlier incidence of both hemorrhagic and ischemic events. In them, the use of intra-aortic balloon pump (IABP) was ten-fold higher. In Kaplan-Meier curves assessing the contribution of both TC and IABP to outcome, IABP was a univariate detrimental factor additive to the role of TC. In a forced Cox model, the relative decline (delta) in platelet count (p=0.05) and the use of IABP (p=0.0001) were both associated with ischemic outcomes. After excluding all patients with IABP, the delta platelet count was no longer significantly associated with ischemic outcomes (p=0.66). After excluding all patients with shock and all those who undergone thrombolysis, there was still a relationship (p=0.0042) between the delta platelet count and ischemic events.

CONCLUSIONS

In this patient population the use of IABP, but not thrombocytopenia per se, is a possible primary cause of worse ischemic outcomes.

Acquired thrombocytopenia after transcatheter aortic valve replacement: clinical correlates and association with outcomes

AIMS

This study aimed to evaluate incidence and correlates for low platelet count after transcatheter aortic valve replacement (TAVR) and to determine a possible association between acquired thrombocytopenia and clinical outcomes.

METHODS AND RESULTS

Patients undergoing TAVR from two medical centres were included in the study. They were stratified according to nadir platelet count post procedure: no/mild thrombocytopenia, ≥100 × 10(9)/L; moderate, 50-99 × 10(9)/L; and severe, <50 × 10(9)/L. A total of 488 patients composed of the study population (age 84.7 ± 7.5 years). At a median time of 2 days after TAVR, 176 patients (36.1%) developed significant thrombocytopenia: 149 (30.5%) moderate; 27 patients (5.5%) severe. Upon discharge, the vast majority of patients (90.2%) had no/mild thrombocytopenia. Nadir platelet count <50 × 10(9)/L was highly specific (96.3%), and a count <150 × 10(9)/L highly sensitive (91.2%), for predicting 30-day death (C-statistic 0.76). Patients with severe acquired thrombocytopenia had a significantly higher mortality rate at 1 year (66.7% for severe vs. 16.0% for no/mild vs. 20.1% for moderate; P < 0.001). In multivariate logistic regression, severe thrombocytopenia was independently associated with 1-year mortality (hazard ratio 3.44, CI: 1.02-11.6; P = 0.046).

CONCLUSIONS

Acquired thrombocytopenia was common after TAVR and was mostly resolved at patient discharge. The severity of thrombocytopenia after TAVR could be used as an excellent, easily obtainable, marker for worse short- and long-term outcomes after the procedure.

Thrombocytopenia in critically ill patients receiving thromboprophylaxis: frequency, risk factors, and outcomes

BACKGROUND

Thrombocytopenia is the most common hemostatic disorder in critically ill patients. The objective of this study was to describe the incidence, risk factors, and outcomes of thrombocytopenia in patients admitted to medical-surgical ICUs.

METHODS

Three thousand seven hundred forty-six patients in 67 centers were enrolled in a randomized trial in which unfractionated heparin was compared with low-molecular-weight heparin (LMWH) for thromboprophylaxis. Patients who had baseline platelet counts < 75 × 10(9)/L or severe coagulopathy at screening were excluded. We analyzed the risk of developing mild (100-149 × 10(9)/L), moderate (50-99 × 10(9)/L), and severe (< 50 × 109/L) thrombocytopenia during an ICU stay. We also assessed independent and time-varying predictors of thrombocytopenia and the effect of thrombocytopenia on major bleeding, transfusions, and death.

RESULTS

The incidences of mild, moderate, and severe thrombocytopenia were 15.3%, 5.1%, and 1.6%, respectively. The predictors of each category of thrombocytopenia were APACHE (Acute Physiology and Chronic Health Evaluation) II score, use of inotropes or vasopressors, and renal replacement therapy. The risk of moderate thrombocytopenia was lower in patients who received LMWH thromboprophylaxis but higher in surgical patients and in patients who had liver disease. Each category of thrombocytopenia was associated with subsequent bleeding and transfusions. Moderate and severe thrombocytopenia were associated with increased ICU and hospital mortality.

CONCLUSION

A high severity of illness, prior surgery, use of inotropes or vasopressors, renal replacement therapy, and liver dysfunction are associated with a higher risk of thrombocytopenia developing in the ICU, whereas LMWH thromboprophylaxis is associated with a lower risk. Patients who develop thrombocytopenia in the ICU are more likely to bleed, receive transfusions, and die.

Decline in platelet count and long-term post-PCI ischemic events: implication of the intra-aortic balloon pump

AIMS

Thrombocytopenia (TC) following a percutaneous coronary intervention (PCI) has been associated not only with hemorrhagic, but also with ischemic outcomes. The purpose of this study was to re-examine the relationship of TC with ischemic events at a 1-year follow-up, and investigate the possible associations.

METHODS AND RESULTS

We studied a real-world, unselected population of ischemic patients undergoing PCI, totaling 861 patients-year, and divided into two groups: with TC (delta platelet count ≥25% from baseline to post-PCI during the hospital admission) and without TC. Compared with patients without TC, patients with TC had a higher and earlier incidence of both hemorrhagic and ischemic events. In them, the use of intra-aortic balloon pump (IABP) was ten-fold higher. In Kaplan-Meier curves assessing the contribution of both TC and IABP to outcome, IABP was a univariate detrimental factor additive to the role of TC. In a forced Cox model, the relative decline (delta) in platelet count (p=0.05) and the use of IABP (p=0.0001) were both associated with ischemic outcomes. After excluding all patients with IABP, the delta platelet count was no longer significantly associated with ischemic outcomes (p=0.66). After excluding all patients with shock and all those who undergone thrombolysis, there was still a relationship (p=0.0042) between the delta platelet count and ischemic events.

CONCLUSIONS

In this patient population the use of IABP, but not thrombocytopenia per se, is a possible primary cause of worse ischemic outcomes.

Thrombocytopenia in patients with atrial fibrillation on oral anticoagulation undergoing percutaneous coronary intervention

Thrombocytopenia is often regarded as a risk factor for bleeding complications in patients undergoing percutaneous coronary intervention (PCI). The risk of mild to moderate baseline and acquired thrombocytopenia on bleeding and thrombotic or thromboembolic complications in patients with atrial fibrillation on oral anticoagulation therapy undergoing PCI, however, remains largely unknown. Management of Patients With Atrial Fibrillation undergoing Coronary Artery Stenting is a multicenter European prospective registry enrolling patients with atrial fibrillation undergoing PCI. We assessed the rate of bleeding complications as defined by Bleeding Academic Research Consortium and a composite of major adverse cardiac and cerebrovascular events (MACCE) including all-cause mortality, myocardial infarction, transient ischemic attack or stroke, stent thrombosis, systemic arterial embolism, or revascularization; and a composite of any harmful event (Bleeding Academic Research Consortium and MACCE) at 12-month follow-up in 861 consecutive patients undergoing PCI. Patients were divided into those with mild to moderate baseline thrombocytopenia (platelet count <150 × 10⁹/L; n = 99) and control group (platelet count >150 × 10⁹/L; n = 762). At hospital discharge, thrombocytopenia had no effect on prescribed antithrombotic treatment, and triple therapy (vitamin K antagonist + aspirin + clopidogrel) was the most common combination in both patient groups (69% vs 73%, p = 0.40). No differences in all-cause mortality (12% vs 11%, p = 0.79), MACCE (23% vs 22%, p = 0.87), or bleeding complications (23% vs 19%, p = 0.26) were detected. Acquired in-hospital thrombocytopenia occurred in 9.7% of patients, and it was associated with similar risk of adverse outcomes compared with control group. In conclusion, mild to moderate baseline thrombocytopenia does not seem to have a clinically significant effect on bleeding or thrombotic or thromboembolic complications after PCI in these frail patients receiving multiple antithrombotic drugs.

Comparison of bleeding complications and one-year survival of low molecular weight heparin versus unfractioned heparin for acute myocardial infarction in elderly patients. The FAST-MI registry

BACKGROUND

There are limited data on the safety and efficacy of low molecular weight heparin (LMWH) in elderly patients with acute myocardial infarction (AMI).

METHODS

We aimed to compare LMWH with unfractioned heparin (UFH) in the management of AMI in elderly patients. FAST-MI is a nationwide registry carried out over a 1-month period in 2005, including consecutive patients with AMI admitted to intensive care unit <48 h from symptom onset in 223 participating centers. We assessed the impact of LMWH on bleeding, the need for blood transfusion and one-year survival in elderly patients (≥ 75 years).

RESULTS

963 patients treated with heparin were included (mean age 82 ± 5 years; 51% women; 42.5% ST-elevation myocardial infarction). Major bleeding (2.4% vs. 6.1%, P=0.004) and blood transfusions (4.6% vs. 9.7%, P=0.002) were significantly less frequent with LMWH compared with the UFH, a difference that persisted after multivariate adjustment (OR=0.41, 95% CI: 0.20-0.83 and OR=0.49, 95% CI: 0.28-0.85, respectively). One-year survival and stroke and reinfarction-free survival were also significantly higher with LMWH compared with UFH (OR=0.66, 95% CI: 0.50-0.85 and OR=0.71, 95% CI: 0.56-0.91, respectively). In two cohorts of patients matched on a propensity score for getting LMWH and with similar baseline characteristics (328 patients per group), major bleeding and transfusion were significantly lower while one-year survival was significantly higher in patients receiving LMWH.

CONCLUSIONS

The present data show that in elderly patients admitted for AMI, use of LMWH is associated with less bleeding, less need for transfusion, and higher survival, compared with the use of UFH.

The Role of Glycoprotein IIb/IIIa Inhibitors- A Promise Not Kept?

For over one decade Glycoproteins IIb/IIIa inhibitors (GPI) have been administered to prevent coronary artery thrombosis. Initially these agents were used for acute coronary syndromes and subsequently as adjunctive pharmacotherapy for percutaneous coronary interventions (PCIs).

Most benefit of GPI emerged from reduction of ischemic events: mostly non-q-wave myocardial infarctions (NQWMIs) during PCI. However, individual randomized clinical trials could not demonstrate that any of these agents could significantly reduce mortality in any clinical subset of patients. Studies of employing prolonged oral GPI administration resulted in excessive death. The non-homogenous statistically-significant reduction of ischemic endpoints was accompanied by an excess of bleeding, vascular complications, and thrombocytopenia. The clinical and ecomomic burden of major bleeding and thrombocytopenia is substantial. The ACUITY trial has initiate a new debate regarding the efficacy and safety of GPI.

Selective “patient-tailored” use of GPI limited to moderate-high risk PCI patients with low bleeding propensity is suggested. Research of new algorithms emphasizing abbreviated GPI administration, careful access site and bleeding surveillance, in conjunction with lower doses of unfractionated heparin or new and safer anti-thrombins may further enhance patient safety.

Thrombocytopenia following percutaneous coronary intervention

BACKGROUND

Thrombocytopenia following percutaneous coronary intervention (PCI) is an underappreciated condition that is often clinically challenging. There are no guidelines on the management of patients with this condition.

OBJECTIVE

To review recent data in etiologies, risk factors, prevention, management, and prognostic implications of thrombocytopenia following PCI.

EVIDENCE ACQUISITION

Search of MEDLINE, EMBASE, the Cochrane Database, and Google Scholar using the term thrombocytopenia + PCI and other relevant keywords to identify systematic reviews, clinical trials, cohort studies, case series, and case reports. The review was limited to English-language articles published between January 1980 and June 2009. Articles on patients with baseline thrombocytopenia prior to PCI were excluded.

EVIDENCE SYNTHESIS

Thrombocytopenia is not infrequent following PCI. The typical patient with post-PCI thrombocytopenia is on multiple therapies that can potentially cause a decrease in the platelet count. Identification of the cause is critical because management of the condition varies significantly based on the etiology. The severity of the thrombocytopenia also determines the clinical management of the patient. Several observational studies have demonstrated the adverse prognostic impact of the complication on clinical outcomes and have identified risk factors.

CONCLUSIONS

Judicious use of therapies that can cause thrombocytopenia, efficient detection of the cause of the decrease in platelet count, and appropriate management of the condition can potentially improve the quality of care and outcomes following PCI. Further research into risk factors that predispose post-PCI patients to developing thrombocytopenia is warranted.

Incidence and clinical consequences of acquired thrombocytopenia after antithrombotic therapies in patients with acute coronary syndromes: results from the Acute Catheterization and Urgent Intervention Triage Strategy (ACUITY) trial

BACKGROUND

The aim of the study was to investigate the incidence and clinical consequences of acquired thrombocytopenia in patients with acute coronary syndromes (ACS) in the ACUITY trial.

METHODS

We examined 10,836 patients with ACS randomized to receive heparin plus glycoprotein (GP) IIb/IIIa inhibitor, bivalirudin plus GP IIb/IIIa inhibitor, or bivalirudin monotherapy.

RESULTS

Acquired thrombocytopenia developed in 740 (6.8%) patients; mild (100,000-150,000 platelets/mm³), moderate (50,000-100,000 platelets/mm³), and severe (< 50,000 platelets/mm³) developed in 656 (6%), 51 (0.5%), and 33 (0.3%) patients, respectively. Patients with acquired thrombocytopenia, compared with those without, were more likely to develop major bleeding (14% vs 4.3%, P < .0001) at 30 days and had higher rates of mortality (6.5% vs 3.4%, P < .0001) at 1 year. By multivariate analysis, acquired thrombocytopenia was an independent predictor of major bleeding at 30 days (hazard ratio [HR] 1.68, 95% CI 1.04-2.72, P = .03). Moderate and severe acquired thrombocytopenia were predictors of mortality at 1 year (HR 2.89, 95% CI 0.92-9.06, P = .06, and HR 3.41, 95% CI 1.09-10.68, P = .03, respectively). Compared to heparin plus GP IIb/IIIa inhibitor, bivalirudin monotherapy was associated with less declines in platelet count by >25% (7.6% vs 5.6%, P = .0009) and >50% (1.4% vs 0.7%, P = .004) from baseline.

CONCLUSIONS

Acquired thrombocytopenia occurs in approximately 1 in 14 patients with ACS treated with antithrombin and antiplatelet medications and is strongly associated with hemorrhagic and ischemic complications. Compared to an anticoagulant regimen including a GP IIb/IIIa inhibitor, administration of bivalirudin monotherapy appears to be associated with less frequent declines in platelet count.

Impact of baseline thrombocytopenia on the early and late outcomes after ST-elevation myocardial infarction treated with primary angioplasty: analysis from the Harmonizing Outcomes with Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial

BACKGROUND

Thrombocytopenia (TP) is a common abnormality in patients presenting with acute coronary syndrome. Whether baseline TP has any influence on the outcome of patients treated with primary angioplasty for acute myocardial infarction is unknown.

METHODS

We sought to detect the impact of baseline TP on the early and late outcomes of patients with ST-elevation myocardial infarction in the HORIZONS-AMI trial that included a protocol of immediate angiography and primary percutaneous coronary intervention.

RESULTS

Baseline TP was found in 4.2% of patients and was associated with a higher incidence of cardiovascular mortality, major bleeding, and major cardiovascular events at short- and long-term follow-up. The 30-day rates of death, major bleeding, major cardiac events, and major cardiac events plus major bleeding were 6.2%, 11.9%, 9.6%, and 18.5% in the TP group, respectively, compared with 2.1%, 7%, 5.2%, and 10.8% in those without TP (P < .05 for all). Similarly, event rates at 2 years were 11.3%, 12.7%, 24.7%, and 30.8% compared with 5.1%, 7.9%, 18.5%, and 23.3% (P < .05). By multivariate analysis, baseline TP was an independent predictor of 30-day net adverse clinical events but not of any 2-year events.

CONCLUSIONS

We found that baseline TP in patients with ST-elevation myocardial infarction undergoing routine angiography and primary percutaneous coronary intervention is strongly associated with early adverse events and is a maker of late events, related to both ischemia and bleeding.

Decline in platelet count in patients treated by percutaneous coronary intervention: definition, incidence, prognostic importance, and predictive factors

AIMS

We investigated the incidence, predictors, and prognostic impact of a decline in platelet count (DPC) in patients treated by percutaneous coronary intervention (PCI).

METHODS AND RESULTS

A total of 10 146 consecutive patients treated by PCI from 2003 to 2006 were included. According to the magnitude of the DPC, the population was divided into four groups: no DPC (<10%), minor DPC (10-24%), moderate DPC (25-49%), and severe DPC (>or=50%). The primary haemorrhagic endpoint was a composite of post-procedure surgical repair major bleeding. The primary ischaemic endpoint was 30-day all-cause mortality-non-fatal myocardial infarction. Among the total population, 36% had a DPC <10%, 47.7% had a DPC of 10-24%, 14% had a DPC of 25-49%, and 2.3% had a DPC >or=50%. On multivariate analysis, moderate and severe DPC were independent predictive factors of the ischaemic outcome. Two procedural practices were identified that, if modified, might reduce the incidence of acquired thrombocytopaenia. Both the intraprocedural use of heparin (as opposed to bivalirudin) and of low molecular weight contrast material were independently associated with severe acquired thrombocytopaenia.

CONCLUSION

Moderate and severe DPC are independent predictors of adverse bleeding and ischaemic outcomes in PCI. Adoption of intraprocedural anticoagulant other than heparin and avoidance of a low molecular weight contrast agent could potentially decrease the occurrence of severe acquired thrombocytopaenia.

Gastrointestinal bleeding in patients with acute coronary syndromes: incidence, predictors, and clinical implications: analysis from the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial

OBJECTIVES

We assessed the incidence, predictors, and outcomes of gastrointestinal bleeding (GIB) in patients with acute coronary syndromes (ACS).

BACKGROUND

GIB is a potential hemorrhagic complication in patients with ACS treated with antithrombotic and/or antiplatelet medications. The clinical outcomes associated with GIB in this setting have not been systematically studied.

METHODS

In the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial, 13,819 patients with moderate- and high-risk ACS, enrolled at 450 centers in 17 countries between August 2003 and December 2005, were randomized to the open-label use of 1 of 3 antithrombin regimens (heparin plus a glycoprotein IIb/IIIa inhibitor, bivalirudin plus a glycoprotein IIb/IIIa inhibitor, or bivalirudin monotherapy).

RESULTS

GIB within 30 days occurred in 178 patients (1.3%). Older age, baseline anemia, longer duration of study drug administration before angiogram, smoking, ST-segment deviation>or=1 mm, and diabetes were identified as independent predictors of GIB. On multivariable analysis, GIB was strongly associated with 30-day all-cause mortality (hazard ratio [HR]: 4.87 [interquartile range (IQR) 2.61 to 9.08], p<0.0001), cardiac mortality (HR: 5.35 [IQR 2.71 to 10.59], p<0.0001), and composite ischemia (HR: 1.94 [IQR 1.14 to 3.30], p=0.014), as well as with 1-year all-cause mortality (HR: 3.97 [IQR 2.64 to 5.99], p<0.0001), cardiac mortality (HR: 3.77 [IQR 2.14 to 6.63], p<0.0001), myocardial infarction (HR: 1.74 [IQR 1.01 to 3.02], p=0.047), and composite ischemia (HR: 1.90 [IQR 1.37 to 2.64], p=0.0001). Patients who experienced GIB had significantly higher rates of stent thrombosis compared with patients without GIB (5.8% vs. 2.4%, p=0.009).

CONCLUSIONS

GIB is a serious condition in the scenario of ACS and is independently associated with mortality and ischemic complications.

Bivalirudin in patients undergoing primary angioplasty for acute myocardial infarction (HORIZONS-AMI): 1-year results of a randomised controlled trial

BACKGROUND

In the HORIZONS-AMI trial, patients with acute ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI) who were treated with the thrombin inhibitor bivalirudin had substantially lower 30-day rates of major haemorrhagic complications and net adverse clinical events than did patients assigned to heparin plus a glycoprotein IIb/IIIa inhibitor (GPI). Here, we assess whether these initial benefits were maintained at 1 year of follow-up.

METHODS

Patients aged 18 years or older were eligible for enrolment in this multicentre, open-label, randomised controlled trial if they had STEMI, presented within 12 h after the onset of symptoms, and were undergoing primary PCI. 3602 eligible patients were randomly assigned by interactive voice response system in a 1:1 ratio to receive bivalirudin (0.75 mg/kg intravenous bolus followed by 1.75 mg/kg per h infusion; n=1800) or heparin plus a GPI (control; 60 IU/kg intravenous bolus followed by boluses with target activated clotting time 200-250 s; n=1802). The two primary trial endpoints were major bleeding and net adverse clinical events (NACE; consisting of major bleeding or composite major adverse cardiovascular events [MACE; death, reinfarction, target vessel revascularisation for ischaemia, or stroke]). This prespecified analysis reports data for the 1-year follow-up. Analysis was by intention to treat. Patients with missing data were censored at the time of withdrawal from the study or at last follow-up. This trial is registered with ClinicalTrials.gov, number NCT00433966.

FINDINGS

1-year data were available for 1696 patients in the bivalirudin group and 1702 patients in the control group. Reasons for participant dropout were loss to follow-up and withdrawal of consent. The rate of NACE was lower in the bivalirudin group than in the control group (15.6%vs 18.3%, hazard ratio [HR] 0.83, 95% CI 0.71-0.97, p=0.022), as a result of a lower rate of major bleeding in the bivalirudin group (5.8%vs 9.2%, HR 0.61, 0.48-0.78, p<0.0001). The rate of MACE was similar between groups (11.9%vs 11.9%, HR 1.00, 0.82-1.21, p=0.98). The 1-year rates of cardiac mortality (2.1%vs 3.8%, HR 0.57, 0.38-0.84, p=0.005) and all-cause mortality (3.5%vs 4.8%, HR 0.71, 0.51-0.98, p=0.037) were lower in the bivalirudin group than in the control group.

INTERPRETATION

In patients with STEMI undergoing primary PCI, anticoagulation with bivalirudin reduced the rates of net adverse clinical events and major bleeding at 1 year compared with treatment with heparin plus a GPI. This finding has important clinical implications for the selection of optimum treatment strategies for patients with STEMI.

FUNDING

Cardiovascular Research Foundation, with unrestricted grant support from Boston Scientific Corporation and The Medicines Company.

Incidence and prognostic significance of thrombocytopenia developed during acute coronary syndrome in contemporary clinical practice

BACKGROUND

Prior studies examining thrombocytopenia among patients with acute coronary syndromes (ACS) evaluated highly selected patients in a clinical trial setting using varying definitions of thrombocytopenia. The incidence, severity, and prognostic significance of acquired thrombocytopenia during ACS in community practice have not been well defined.

METHODS AND RESULTS

We examined 36 182 patients with non-ST-segment elevation ACS enrolled at 379 US hospitals participating in the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the American College of Cardiology/American Heart Association Guidelines (CRUSADE) quality improvement initiative between June 2004 and December 2006. Patients with baseline platelet counts <150x10(9)/L were excluded. Overall, 4697 patients (13%) developed new thrombocytopenia, defined as nadir platelet count <150x10(9)/L (referenced lower limit of normal), during their ACS hospitalization. Risks of in-hospital mortality and bleeding correlated directly with severity of thrombocytopenia; even mild thrombocytopenia (nadir 100 to 149x10(9)/L) was associated with increased risks of mortality (adjusted odds ratio [OR], 2.01; 95% CI, 1.69 to 2.38) and bleeding (adjusted OR, 3.76; 95% CI, 3.43 to 4.12). Each 10% drop in platelet count was associated with increased mortality and bleeding risks (adjusted ORs, 1.39 [95% CI, 1.33 to 1.46] and 1.89 [95% CI, 1.83 to 1.95], respectively). A >/=50% drop in platelet count was associated with higher risk of adverse outcomes regardless of the nadir count. A novel combined definition of acquired thrombocytopenia-nadir <150x10(9)/L or platelet count drop >or=50%-identifies a population of ACS patients at higher risk of mortality and major bleeding (adjusted ORs, 2.58 [95% CI, 2.23 to 2.98] and 4.32 [95% CI, 3.97 to 4.70], respectively).

CONCLUSIONS

Thrombocytopenia, a common complication of ACS, is associated with increased mortality and bleeding risks. Even mild thrombocytopenia or a platelet count drop >/=50% in the setting of normal nadir values is clinically significant. Application of a combined definition for thrombocytopenia using both absolute and relative thresholds permits increased sensitivity for patients at high risk of adverse outcomes.

Occurrence, predictors, and outcomes of post-percutaneous coronary intervention thrombocytopenia in an unselected population

OBJECTIVES

We sought to determine the occurrence, predictors, and prognostic impact of post-percutaneous coronary intervention (post-PCI) thrombocytopenia on an unselected real-world patient population.

BACKGROUND

Thrombocytopenia after PCI has been shown to portend worse prognosis in clinical trials. The significance of post-PCI thrombocytopenia has not previously been examined outside the clinical trial setting.

METHODS

The study cohort consisted of 1,302 consecutive patients with normal baseline platelet count (150 x 10(9)/L). Post-PCI thrombocytopenia was defined as nadir platelet count <100 x 10(9)/L or a drop >50% from baseline. The primary outcomes were in-hospital and 6-month rates of death and major adverse cardiovascular events (MACE), and the secondary outcomes were bleeding, need for blood transfusion, and length of hospital stay. Logistic regression was performed to identify independent predictors.

RESULTS

Post-PCI thrombocytopenia developed in 41 patients (occurrence 3.1%). Independent predictors were baseline creatinine clearance (odds ratio [OR] 1.02 for every unit decrease, 95% confidence interval [CI] 1.01-1.03, P=0.001), failed PCI (OR 3.8, CI 1.6-9.4, P=0.003), and use of intraaortic balloon pump (OR 2.8, CI 1.1-6.8, P=0.024). All study outcomes were significantly higher in patients with post-PCI thrombocytopenia. Post-PCI thrombocytopenia independently predicted MACE at 6 months (hazard ratio 2.7, CI 1.3-5.5, P=0.0069) and all the secondary outcomes.

CONCLUSIONS

Post-PCI thrombocytopenia occurred in 3.1% of patients in an unselected real-world population and carried a significant detrimental impact on prognosis. Failed PCI was the strongest correlate identified.

Thrombocytopenia at baseline is a predictor of inhospital mortality in patients undergoing percutaneous coronary intervention

BACKGROUND

Thrombocytopenia (TP) is a common baseline abnormality in patients undergoing percutaneous coronary intervention (PCI). Whether TP has any influence on the outcome of PCI patients is unknown. Our aim was to determine if TP at baseline impacts on inhospital mortality in patients undergoing PCI at our institution.

METHODS

From April 2000 until October 2005, 11,021 PCI procedures were performed at the University Health Network in Toronto, Canada. Baseline platelet count was recorded in 10,821 (98.2%) cases. Patients with platelets <150 x 10(9)/L were assigned to the TP group (n = 639), and those with > or =150 x 10(9)/L to the normal platelet group (n = 10,182). Clinical, angiographic, procedural, and inhospital outcome data were collected prospectively. Multivariable analysis was performed using logistic regression.

RESULTS

In-hospital death rate was higher in the TP group (1.9% vs 0.6%, P < .001) due to an increased mortality in TP patients undergoing urgent (3.55% vs 1.15%, P < .001) but not elective (0% vs 0.04%, P = 1.0) PCI. Major bleeding (1.7% vs 0.8%, P < .05) and gastrointestinal bleeding (1.1% vs 0.5%, P < .05) complications were greater in the TP group. Multivariate analysis demonstrated that baseline TP was an independent predictor of inhospital mortality (odds ratio 2.07 [1.1-4.1], P = .035).

CONCLUSIONS

Baseline TP is an independent predictor of inhospital mortality in patients undergoing PCI for urgent indications. Thrombocytopenia should be considered an important addition to PCI risk prediction models to improve their precision and clinical applicability.

Safety and efficacy of bivalirudin monotherapy in patients with diabetes mellitus and acute coronary syndromes: a report from the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial

OBJECTIVES

We sought to evaluate clinical outcomes of patients with diabetes mellitus in the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial, overall and by treatment arm.

BACKGROUND

In the ACUITY trial, 13,819 patients with moderate- or high-risk acute coronary syndromes (ACS) were randomized to heparin (unfractionated or enoxaparin) plus glycoprotein IIb/IIIa inhibition (GPI), bivalirudin plus GPI, or bivalirudin monotherapy. Compared with heparin plus GPI, bivalirudin monotherapy resulted in similar protection from ischemic events with less major bleeding. Whether these results apply to patients with diabetes is unknown.

METHODS

We evaluated the impact of diabetes on 30-day net adverse clinical outcomes (composite ischemia [death, myocardial infarction, or unplanned ischemic revascularization] or major bleeding), overall and by antithrombotic strategy.

RESULTS

Diabetes was present in 3,852 randomized patients (27.9%). Compared with nondiabetic patients, diabetic patients had higher 30-day rates of net adverse clinical outcomes (12.9% vs. 10.6%; p < 0.001), composite ischemia (8.7% vs. 7.2%; p = 0.003), and major bleeding (5.7% vs. 4.2%; p < 0.001). Among diabetic patients, compared with heparin plus GPI, bivalirudin plus GPI resulted in similar rates of net adverse clinical outcomes (14.0% vs. 13.8%; p = 0.89), while bivalirudin monotherapy resulted in a similar rate of composite ischemia (7.9% vs. 8.9%; p = 0.39) and less major bleeding (3.7% vs. 7.1%; p < 0.001), yielding fewer net adverse clinical outcomes (10.9% vs. 13.8%; p = 0.02).

CONCLUSIONS

Diabetic patients with ACS managed invasively have higher rates of composite ischemia and major bleeding. Compared with treatment with heparin plus GPI, bivalirudin monotherapy provides similar protection from ischemic events with less major bleeding, resulting in a significant reduction in net adverse clinical outcomes.