Antiphospholipid antibodies in patients with previous myocardial infarction

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.

The adjusted Global AntiphosPholipid Syndrome Score (aGAPSS) for risk stratification in young APS patients with acute myocardial infarction

BACKGROUND

Young adults with acute myocardial infarction are a critical group to examine for the purpose of risk factor stratification and modification. In this study we aimed to assess the clinical utility of the adjusted Global AntiphosPholipid Syndrome Score (aGAPSS) for the risk stratification of acute myocardial infarction in a cohort of young patients with antiphospholipid syndrome (APS).

METHODS

The analysis included 83 consecutive APS patients (≤50years old) who presented with arterial or venous thromboembolic events. Data on cardiovascular risk factors and antiphospholipid antibodies (aPL) positivity were retrospectively collected. The aGAPSS was calculated by adding the points corresponding to the risk factors, based on a linear transformation derived from the ß-regression coefficient as follows: 3 for hyperlipidaemia, 1 for arterial hypertension, 5 for aCL IgG/IgM, 4 for anti-b2 glycoprotein I IgG/IgM and 4 for LA.

RESULTS

Higher aGAPSS values were observed in patients with acute myocardial infarction when compared to the others [mean aGAPSS 11.9 (S.D. 4.15, range 4-18) Vs. mean aGAPSS 9.2 (S.D. 5.1, range 1-17); T test: p<0.05]. Significantly higher aGAPSS values were also seen in patients with acute coronary syndrome compared to patients with a history of peripheral or cerebrovascular arterial thrombotic events [mean aGAPSS 11.9 (S.D. 4.15, range 4-18) Vs. mean aGAPSS 6.7 (S.D. 5.7, range 1-17); T test: P<0.005].

CONCLUSIONS

The aGAPSS is based upon a quantitative score and could aid risk stratifying APS patients younger than 50years for the likelihood of developing coronary thrombotic events and may guide pharmacological treatment for high-risk patients.

Thrombophilic state in young patients with acute myocardial infarction

The prevalence of thrombophilia and dyslipidemia among young survivors of acute coronary syndrome has not been clearly defined. The purpose of the current study was to investigate the prevalence of multiple markers of thrombophilia and dyslipidemia in a cohort of consecutive young survivors of acute coronary syndrome. The study cohort included 156 consecutive young patients (men <45 and women <50 years), admitted to the intensive cardiac care unit with newly diagnosed acute coronary syndrome. Analysis included baseline, clinical and epidemiological characteristics, angiographic coronary anatomy, echocardiographic evaluation, extensive lipid and thrombophilia laboratory profiles, and in-hospital and 1-year clinical outcomes for all patients. Acute myocardial infarction was diagnosed in 142 (92 %) patients, of whom 108 (72 %) had ST-segment elevation. Eighteen (12 %) patients had no traditional risk factors. Low levels of high-density lipoprotein (<40 mg/dL) were found in 101 (65 %) patients, and 49 (34 %) patients had elevated levels of lipoprotein(a) (Lp(a)) (>30 mg/dL). Eighteen (12 %) patients were diagnosed with antiphospholipid antibody syndrome (APS), and 73 (47 %) had at least one laboratory finding consistent with thrombophilia. Patients with APS had significantly higher levels of Lp(a) (46 ± 32 vs. 29 ± 31 mg/dL, p = 0.005). APS is a common prothrombotic state found in young survivors of acute coronary syndrome. Lp(a) levels are elevated among APS patients who present with premature acute coronary syndrome.

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.

Anticardiolipin antibodies and acute myocardial infarction in non-systemic lupus erythmatosus patients: a controlled prospective study

PURPOSE

To examine the prevalence of anticardiolipin antibodies (ACLA) in relatively young patients with acute myocardial infarction (MI) and their role in subsequent coronary and thromboembolic events in the post-MI period.

PATIENTS AND METHODS

In 124 relatively young survivors (aged 65 or younger) of acute MI, ACLA were measured in a controlled prospective study on admission and 3 months later. Myocardial reinfarction and thromboembolic events during a mean follow-up period of 19 +/- 3 months were diagnosed by standard tests.

RESULTS

Seventeen (14%) of the 124 patients were ACLA positive (either IgM or IgG) upon admission compared with 2 out of 76 (3%) of the control group matched for age and coronary risk factors (P < 0.01). The levels of ACLA remained unchanged in all but 1 patient 3 months later. During the follow-up period the rate of thromboembolic events and myocardial reinfarction was significantly higher in the ACLA-positive patients as compared with the ACLA-negative group: 41% versus 4% (P < 0.0001) and 35% versus 10% (P < 0.05), respectively. Using logistic regression, high titer of ACLA was found to be the only independent risk factor for subsequent thromboembolic events or myocardial reinfarction after acute MI.

CONCLUSIONS

High prevalence of ACLA was found in relatively young survivors of acute MI. The presence of ACLA is a marker for increased risk of subsequent myocardial reinfarction and thromboembolic events after acute MI.

[The heart and antiphospholipid antibodies. Personal experience and review of the literature]

Since the recognition of the antiphospholipid syndrome, a great number of cardiac manifestations have been reported in association with these antibodies: valvular disease, coronary artery disease, cardiomyopathy and intracardiac thrombosis. However this association raises numerous questions related to the pathogenic role of antiphospholipids, their prognostic significance and their frequency in a non-selected population with a definite cardiac manifestation. In view of the literature and our personal experience, it seems necessary to distinguish two kinds of situations. During systemic lupus and primary antiphospholipid syndrome (which must be systematically looked for in patients with history of thrombo-embolic disease), antiphospholipids antibodies certainly play a role in the occurrence of cardiac manifestations, but the precise place of thrombosis has to be best defined along with immunologic/inflammatory mechanisms. On the other hand, in a non-selected population, antiphospholipids antibodies may just be the consequence of the cardiac lesion and do not seem to have prognostic implications. This distinction, actually hypothetical, should be supported on the basis of distinct specificities of antiphospholipids antibodies and especially their dependence on beta 2-glycoprotein I, which would help to distinguish the harmful antibodies from those which probably just appear as an epiphenomenon.

The presence of antiphospholipid antibodies in acute myocardial infarction

This study was undertaken to determine if there is an association between increased titers of five different antiphospholipid antibodies (aPLA) in young patients' sera and the occurrence of acute myocardial infarction (AMI). Antibodies to anticardiolipin (aCL), anti-phosphatidylserine (aPS), antiphosphatidylinositol (aPI), anti-phosphatidylcholine (aPC), and anti-phosphatidylethanol amine (aPEA) were measured in 214 patients (102 patients, 102 healthy controls and 10 patients with antiphospholipid syndrome). These antibodies were measured twice (within 4h of onset of acute myocardial ischemic chest pain and 3 months after the myocardial infarction) by enzyme linked immunosorbent assay (ELISA). Elevated titers of four different aPLA were detected in 6.9% of all patients with AMI on hospitalization. Titers of aPLA in AMI were elevated in the younger age group < 50 years old (P < 0.001) and in men only (not statistically significant). No correlation was found between the presence of aPLA and cardiovascular risk factors (smoking, hypertension, diabetes mellitus and hyper-cholesterolemia). Three of the seven patients with increased titers of aPLA did not have any other cardiovascular risk factors. The titers of aPLA were within normal range 3 months after AMI. Evidence of significantly elevated titers of different aPLA at the early stage of AMI suggests that these autoantibodies are present before the AMI and are not secondary to them. The disappearance of the elevated aPLA 3 months after AMI may be due to an absorption effect or possibly a cyclic phenomenon similarly found in other autoimmune diseases. aPLA may be an additional risk factor for AMI, and should especially be considered in a patient of the younger age group without apparent cardiovascular risk factors.