Lipoprotein (a) and anticardiolipin antibodies are risk factors for clinically relevant restenosis after elective balloon percutaneous transluminal coronary angioplasty

Immunoglobulin G (IgG) anticardiolipin antibodies and recurrent cardiovascular events. A systematic review and Bayesian meta-regression analysis

BACKGROUND

Anticardiolipin antibodies of the immunoglobulin G isotype (IgG aCL) have been suggested as risk factor for arterial and venous thrombosis. No conclusive data in patients with coronary artery disease (CAD) do exist. We investigate the risk of recurrent CAD according to the presence of IgG aCL.

METHODS

We performed a systematic review and meta-analysis to evaluate the risk of recurrent major adverse cardiac events (MACE) associated with the presence of IgG aCL in patients with CAD. MEDLINE and Cochrane databases were searched. We conducted a meta-analysis of the relative risk (RR) both at 12 and 24 months.

RESULTS

We included 11 eligible studies with a total of 2425 patients, 283 IgG aCL+ and 2142 IgG aCL-. The prevalence of IgG aCL+ ranged from 6.1% to 43.3%. A total of 341 cardiac events were reported: 71 (25.1%) in IgG aCL+ and 270 (12.6%) in IgG aCL- patients. We found an increased risk of recurrent MACE in patients with high IgG aCL both at 12 (RR 2.17, 2.5-97.5%CI, 1.54-3.00) and 24 months (RR 2.11, 2.5-97.5%CI, 1.62-2.66). This association was even stronger in patients with juvenile CAD (i.e. <50 years) at both 12 (RR 3.21, 2.5-97.5%CI, 1.74-5.41) and 24 months (RR 3.24, 2.5-97.5%CI, 1.84-5.21).

CONCLUSION

Patients with CAD and elevated IgG aCL have a doubled risk of recurrent MACE at 12 and 24 months. The presence of aCL should be suspected in patients with recurrent CAD events or in patients with juvenile CAD.

Impact of Antiphospholipid Syndrome and/or Systemic Lupus Erythematosus on the Long-term Adverse Cardiovascular Outcomes in Patients After Percutaneous Coronary Intervention: A Systematic Review and Meta-analysis

Antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE) are 2 rare autoimmune disorders which commonly affect women. Several previous studies showed APS to have been evolved from SLE. Secondary APS often coexists with SLE. One common feature relating these 2 diseases are the antiphospholipid antibodies, which are found in most of the patients with APS and in approximately 30% to 40% of patients with SLE, among which, about 10% develop APS. The leading cause of death in these patients is from cardiovascular disease due to accelerated atherosclerosis, which often progresses more rapidly, compared with the general population. However, the impact of APS and/or SLE on the cardiovascular outcomes in patients undergoing percutaneous coronary intervention (PCI) is controversial. Therefore, to solve this issue, we aim to compare the long-term (≥1 year) adverse cardiovascular outcomes after PCI, in patients with APS and/or SLE, and those without these disorders.Medline and EMBASE databases were searched for studies comparing the long-term adverse cardiovascular outcomes between SLE and non-SLE, APS and non-APS, or SLE + APS and non-SLE + non-APS after PCI. We calculated odd ratios (OR) and 95% confidence intervals (CIs) for these categorical variables, and the pooled analyses were performed with RevMan 5.3.Seven studies consisting of a total of 253,436 patients (568 patients in the experimental group and 252,868 patients in the control group) were included in this meta-analysis. During a follow-up period of ≥1 year, mortality and myocardial Infarction (MI) were significantly higher in the experimental group (OR 2.02, 95% CI 1.63-2.49, P < 0.00001 and OR 1.59, 95% CI 1.23-2.05, P = 0.0004, respectively). Major adverse cardiac events and repeated revascularization were also significantly higher in the SLE/APS group (OR 2.40, 95% CI 1.42-4.03, P = 0.001 and OR 2.59, 95% CI 1.26-5.31, P = 0.01, respectively).Antiphospholipid syndrome and SLE are associated with significantly higher long-term (≥1 year) adverse cardiovascular outcomes after PCI. However, because of the limited number of patients and researches done, and due to a larger percentage of heterogeneity observed among several subgroups, this analysis may not generate a powerful result.

Antiphospholipid syndrome and acute myocardial infarction: treatment with thrombectomy and abciximab

Antiphospholipid syndrome (APS) is an autoimmune coagulation disorder that manifests clinically as venous and arterial thrombosis, and may affect any tissue or organ. Coronary artery involvement, however, is very rare. Case reports in the literature describing patients with coronary acute syndrome and APS treated with coronary angioplasty show conflicting results. We report an adult male patient with APS who presented with an acute myocardial infarction. Given the high risk of thrombosis in these patients, he was treated percutaneously with thrombectomy and abciximab. We review the few cases of coronary angioplasty in patients with APS reported to date. To our knowledge, this is the first case in which acute myocardial infarction due to thrombotic coronary occlusion was treated with thrombectomy and abciximab without stenting the artery.

A comparative study of restenosis rates in bare metal and drug-eluting stents

BACKGROUND

Various studies have been performed throughout the world on the rate of restenosis using bare metal stents (BMS) and drug-eluting stents (DES). The prohibitive costs associated with DES generally dictate the type of stent used, especially in developing countries. Therefore, there was a need for a study to assess the effect of various risk factors on restenosis in BMS and DES in the Indian context. A study was performed in the premier institution of the Indian Armed Forces, the Army Hospital (Research and Referral), New Delhi, India, under the aegis of the Indian Council of Medical Research (New Delhi). The profile of patients in the armed forces is inherently diverse in terms of demography, ethnicity, genetics, etc, which reflects the diverse and varied nature of the population in India.

METHODS AND RESULTS

A total of 130 patients were included in the present study. Follow-up after stent implantation was scheduled for six to nine months following the procedure to assess symptoms, drug compliance, and treadmill test and coronary angiography results, and to ascertain the incidence of restenosis. However, only 80 patients returned for follow-up and, therefore, the final analysis was based on these patients. They were segregated into BMS (n=41) and DES (n=39) groups. Restenosis occurred in 29 patients (36.3%). Nine of 39 patients with DES (23.1%) and 20 of 41 patients with BMS (48.8%) developed restenosis. There was a statistically significant relationship between restenosis and female sex, clinical presentation before intervention and at the time of follow-up evaluation (unstable angina), hypertension, positive stress test and compliance with medical therapy (P<0.05). No statistically significant relationship was observed between restenosis and age, diabetes, smoking, obesity and diet (P>0.05).

CONCLUSIONS

DES appear to reduce the restenosis rate and clinical end points, and appear to be more cost effective than BMS. Patient-related factors (eg, sex, hypertension and unstable angina) are important variables that affect the restenosis rate. Noninvasive stress testing had high positive and negative predictive values. Therefore, based on the present study, noninvasive stress testing is suggested before routine angiography at follow-up, which will reduce the need for repeat coronary angiography.

Antiphospholipid syndrome; its implication in cardiovascular diseases: a review

Antiphospholipid syndrome (APLS) is a rare syndrome mainly characterized by several hyper-coagulable complications and therefore, implicated in the operated cardiac surgery patient. APLS comprises clinical features such as arterial or venous thromboses, valve disease, coronary artery disease, intracardiac thrombus formation, pulmonary hypertension and dilated cardiomyopathy. The most commonly affected valve is the mitral, followed by the aortic and tricuspid valve. For APLS diagnosis essential is the detection of so-called antiphospholipid antibodies (aPL) as anticardiolipin antibodies (aCL) or lupus anticoagulant (LA). Minor alterations in the anticoagulation, infection, and surgical stress may trigger widespread thrombosis. The incidence of thrombosis is highest during the following perioperative periods: preoperatively during the withdrawal of warfarin, postoperatively during the period of hypercoagulability despite warfarin or heparin therapy, or postoperatively before adequate anticoagulation achievement. Cardiac valvular pathology includes irregular thickening of the valve leaflets due to deposition of immune complexes that may lead to vegetations and valve dysfunction; a significant risk factor for stroke. Patients with APLS are at increased risk for thrombosis and adequate anticoagulation is of vital importance during cardiopulmonary bypass (CPB). A successful outcome requires multidisciplinary management in order to prevent thrombotic or bleeding complications and to manage perioperative anticoagulation. More work and reporting on anticoagulation management and adjuvant therapy in patients with APLS during extracorporeal circulation are necessary.

Newer antiphospholipid antibodies predict adverse outcomes in patients with acute coronary syndrome

Antiphospholipid antibodies (aPLs) have been implicated in atherogenesis. We studied 344 patients with acute coronary syndromes; approximately 40% were aPL+ in 1 or more tests and 60% aPL-. In 215 patients, coronary artery disease (CAD) was angiographically documented, with 43.7% positive for aPL vs 34.9% of patients without CAD positive for aPLs. Anti-beta(2)-glycoprotein I (beta2GPI; 54%) and anti-oxidized low-density lipoprotein (oxLDL)/beta2GPI (48%) were most frequent, accounting for 87% of all aPL+ CAD cases. aPLs correlated with severity of CAD (P = .012). Adverse events occurred in 16.7% of patients with CAD, more frequently in patients who were aPL+ (P = .0006; relative risk, 2.9; 95% confidence interval, 1.5-5.6). Patients who were aPL+ with severe CAD had more adverse events than patients who were aPL- with severe CAD (P = .005) and aPL+ patients undergoing revascularization procedures (P = .001). Vascular events occurred in 21.7% of aPL+ patients compared with 7.1% of aPL- patients (P = .005). Anti-beta2GPI and anti-oxLDL/beta2GPI were associated with CAD severity and adverse outcomes.

Effect of pioglitazone on atherogenic outcomes in type 2 diabetic patients: a comparison of responders and non-responders

The aim of this study was to evaluate the anti-atherogenic efficacy of pioglitazone, a thiazolidinedione derivative, on the change in atherogenic outcomes by comparing responder and non-responder groups in type 2 diabetic patients. Twenty-three patients with poor diabetic control were treated with 15 mg of pioglitazone for 12 months. The levels of fasting plasma glucose (FPG), HbA1c, triglycerides (TG), total cholesterol (T-Cho), low-density lipoprotein-cholesterol (LDL-C), and high-density lipoprotein-cholesterol (HDL-C) were measured monthly, and those of remnant-like particle-cholesterol (RLP-C) and lipoprotein (a) [Lp (a)] were measured every 3 months. In Month 6, the patients were divided into two groups according to the decrease in HbA1c level: the responder group showed a decrease of > or =1%; the non-responder group, a decrease of <1%. In the responder group, the levels of FPG and HbA1c decreased significantly after Month 3. The values of the body mass index (BMI), homeostasis model assessment of insulin resistance (HOMA-IR) index, LDL-C, and RLP-C were significantly higher in the responder group than in the non-responder group. Although the levels of T-Cho and HDL-C were unchanged in both groups, those of TG and RLP-C were drastically reduced in the responder group. Interestingly, the relative change in Lp (a) was significantly decreased in both groups. These results strongly suggest that pioglitazone is beneficial for type 2 diabetic patients with high levels of BMI, HOMA-IR, LDL-C, and RLP-C, as it helps to prevent the progression of atherosclerosis, including coronary heart diseases.

Renal transplant recipients are at high risk for both symptomatic and asymptomatic deep vein thrombosis

BACKGROUND

Venous thromboembolism (VTE) is one of the thrombotic complications that can occur in patients receiving renal transplantation (RT). The prevalence of VTE in RT patients is, however, undefined.

OBJECTIVES

To evaluate the rate of a first episode of VTE in a series of 538 consecutive RT recipients admitted to our institution, the timing of occurrence of the thromboembolic events after transplantation, and the rate of recurrence after thromboprophylaxis withdrawal. Risk factors for recurrence were also evaluated, particularly in relation to the type of the first event (symptomatic or asymptomatic).

RESULTS

During follow-up, 47 of 518 patients (28 males, 19 females; 9.1%) developed a first episode of VTE at a median time of 17 months (range 1-165 months) after kidney transplantation. Cancer was associated with the occurrence of VTE (odds ratio 4.8). Seventeen of 43 patients (39.5%) with deep vein thrombosis were asymptomatic and the diagnosis was made during routine ultrasound examination. Twenty-two patients (46.8%) experienced a recurrence of VTE. A relevant rate of recurrence was documented amongst patients with a first episode of both symptomatic (53%) and asymptomatic (23.5%) VTE.

CONCLUSION

This study confirms that RT patients are at high risk of symptomatic and asymptomatic VTE and that this risk persists even after several years. Patients who experience VTE are at high risk of recurrence after thromboprophylaxis withdrawal.

Association between anticardiolipin antibodies and recurrent cardiac events in patients with acute coronary syndrome

To determine whether the presence of anticardiolipin (aCL) antibodies in patients with acute coronary syndrome is predictive of recurrent cardiac events in hospital stay and follow-up. The study population consisted of 80 patients with acute coronary syndrome. IgM and IgG aCL levels were determined before hospital discharge. We divided the patients into those with an aCL IgG >or= 40 IgG phospholipid units (group I, n = 30) and those with an aCL IgG < 40 IgG phospholipid units (group II, n = 50). All patients underwent coronary angiography. Follow-up coronary angiography was performed 12 months after percutaneous coronary intervention (PCI). Infectious and autoimmune diseases were exclusion criteria. Patients were observed to determine overall mortality, reinfarction, and restenosis. There were no differences between the groups with respect to the prevalence of hypertension, diabetes mellitus, and cigarette smoking, sex, or ejection fraction. The prevalence of left ventricular thrombus was similar between the groups (group I: 16% versus group II: 16.7%, P > 0.05). Although the presence of left atrial thrombus was much more frequent in cardiolipin positive patients (13% versus 4%, respectively), the difference was not statistically significant (P = 0.19). Restenosis was observed in 40% of the cardiolipin positive patients and 14% of the cardiolipin negative patients (P < 0.01). There was no significant association between reinfarction and anticardiolipin positivity during follow-up (26% versus 10%, P > 0.05). In group I patients, in-hospital mortality was somewhat more frequent compared to group II patients (4% versus 10%), but the difference was not statistically significant (P = 0.27). One year mortality was similar between the groups. These results suggest that 1) restenosis occurs more frequently in anticardiolipin positive patients and 2) no association is evident between positive aCL and mortality, reinfarction, and intracardiac thrombus.

High Rate of Recurrence in Renal Transplant Recipients after a First Episode of Venous Thromboembolism

BACKGROUND

No data are available about the optimal duration of oral anticoagulant therapy (OAT) after an episode of venous thromboembolism (VTE) occurring in renal transplant (RT) recipients. Our study was undertaken to evaluate the risk of VTE recurrence in patients developing a first episode of VTE after RT.

METHODS

Among 484 RT patients, 34 (7%) developed a first VTE: 28/34 VTE patients (Group 1) were prospectively studied, after stopping OAT. Group 1 was compared with a group of 84 patients without history of renal disease who had suffered from a first episode of VTE matched for age, sex and type of thrombotic event (Group 2) and with a matched group of 84 RT recipients with no history of VTE (Group 3). After OAT withdrawal, blood samples were obtained for thrombophilia and clotting activation markers (prothrombin fragment 1+2 (F1+2) and D-dimer plasma levels).

RESULTS

During follow-up, 14/28 patients of Group 1 and 8/84 patients of Group 2 experienced VTE recurrence (P < 0.0005). Homocysteine, F1+2 and D-dimer plasma levels were significantly higher in Group 1 than in Group 2 and 3 (P < 0.0001 and <0.05 respectively) for all the three parameters.

CONCLUSIONS

Our data outline the high risk of VTE recurrence in RT recipients. Strategies for VTE recurrence prevention are needed; Prolonged OAT, in spite of the high bleeding risk of RT patients, should be considered in this respect.

Pre-existing anticardiolipin antibodies and development of restenosis after coronary balloon angioplasty

Immune mechanisms play a critical role in cardiovascular disease. Cardiolipins are candidate autoantigens with a prothrombotic activity of their corresponding antibodies. We investigated the influence of pre-existing immunoglobulin (Ig)M and IgG anticardiolipin (aCL) antibodies on restenosis after coronary balloon angioplasty and their interaction with tissue plasminogen activator, plasminogen activator inhibitor type-1, von Willebrand factor and lipoprotein (a) in 132 patients with stable angina pectoris using immunoassays. Thirty percent of patients developed angiographically proven restenosis estimated by three independent experienced angiographers; 12% of all patients developed recurrent restenoses at the same site during a follow-up period of 2 years. Circulating IgM aCL antibodies categorized by quartiles predicted recurrent restenoses (logistic regression, for trend P < 0.04) with an increase of relative risk (RR) per quartile of 2.09. The predictive value of IgM aCL antibodies was unchanged adjusting for established cardiovascular risk factors (P = 0.028, RR = 2.69), extent of coronary artery disease (P = 0.014, RR = 2.73) and inflammatory parameters (P = 0.025, RR = 2.79), but lost significance adjusting for other prothrombotic parameters (P = 0.24, RR = 1.76). IgM aCL antibodies positively correlated with lipoprotein (a) (r = 0.23, P = 0.04). However, there was no significant interaction between their influences on recurrent restenoses. The other prothrombotic parameters did not predict single or recurrent restenoses. In conclusion, IgM aCL antibodies may help to identify a group of patients at high risk for recurrent restenoses after coronary balloon angioplasty.

Lipoprotein(a): an emerging cardiovascular risk factor

Lipoprotein(a) is a cholesterol-enriched lipoprotein, consisting of a covalent linkage joining the unique and highly polymorphic apolipoprotein(a) to apolipoprotein B100, the main protein moiety of low-density lipoproteins. Although the concentration of lipoprotein(a) in humans is mostly genetically determined, acquired disorders might influence synthesis and catabolism of the particle. Raised concentration of lipoprotein(a) has been acknowledged as a leading inherited risk factor for both premature and advanced atherosclerosis at different vascular sites. The strong structural homologies with plasminogen and low-density lipoproteins suggest that lipoprotein(a) might represent the ideal bridge between the fields of atherosclerosis and thrombosis in the pathogenesis of vascular occlusive disorders. Unfortunately, the exact mechanisms by which lipoprotein(a) promotes, accelerates, and complicates atherosclerosis are only partially understood. In some clinical settings, such as in patients at exceptionally low risk for cardiovascular disease, the potential regenerative and antineoplastic properties of lipoprotein(a) might paradoxically counterbalance its athero-thrombogenicity, as attested by the compatibility between raised plasma lipoprotein(a) levels and longevity.

Restenosis after intracoronary stent placement: can apolipoprotein(a) polymorphism play a role?

BACKGROUND

The relationship between lipoprotein(a) and restenosis after intracoronary stent implantation has been analysed by two specific studies, but the role of apoliprotein(a) polymorphism was not considered. The aim of the present prospective study was to evaluate whether lipoprotein(a) levels and apolipoprotein(a) phenotypes are predictors of restenosis after elective stent implantation in patients with de novo lesions of coronary arteries.

METHODS

We recruited 182 patients with a new lesion successfully treated with elective placement of one or two Palmaz-Schatz stents. Follow-up angiography was scheduled at 6 months or earlier if clinically indicated. Nine patients were lost to the follow up. Among 173 patients enrolled, restenosis was present in 52 (30.0%) and absent in 121 (70.0%).

RESULTS

Lipoprotein(a) levels were higher in the restenosis than in the nonrestenosis group (29.5+/-17.2 versus 27.4+/-20.2 mg/dl), even if the difference did not attain statistical significance (P=0.067). The restenosis group had a percentage of subjects with at least one apolipoprotein(a) isoform of low molecular weight significantly greater than the nonrestenosis group (82.7 versus 66.9%; P=0.035). A multiple logistic regression analysis showed that multiple stenting (RR: 4.01; CI 95%: 1.65-13.91; P=0.004), presence of diabetes (RR: 3.96; CI 95%: 1.67-9.37; P=0.002) and presence of multivessel disease (RR: 2.71; CI 95%: 1.19-6.16; P=0.017) were predictors of restenosis after stent placement. Lipoprotein(a) and apolipoprotein(a) polymorphism did not enter the model as predictive variables.

CONCLUSIONS

Our study confirms that multiple stenting, diabetes and multivessel disease are powerful predictors of restenosis after intracoronary stent implantation. On the contrary, lipoprotein(a) and apolipoprotein(a) polymorphism do not appear to be reliable markers of restenosis in patients with stent implantation.