P260 Left ventricular pseudoaneurysm manifesting as syncope

Introduction

Left ventricular (LV) pseudoaneurysms form when cardiac rupture is contained by adherent pericardium or scar tissue. LV pseudoaneurysm is one of the mechanical complications of myocardial infarctions (MI), particularly inferior wall MI.

Although LV pseudoaneurysms are not common, the diagnosis is difficult and they are prone to rupture. Transthoracic echocardiography is commonly used in clinical practice and is usually sufficient to make the diagnosis of LV pseudoaneurysm. Regardless of treatment, patients with LV pseudoaneurysms had a high mortality rate, especially those who did not undergo surgery.

Description of the clinical case

74 years-old woman, with previous history of hypertension, dyslipidaemia and type 2 diabetes and stable coronary disease. In June 2018 the patient underwent coronary angiography that revealed left main and 3 vessels coronary disease, Cardiac revascularization surgery was proposed that the patient refused. The patient was stable during 6 months. Four days before presenting to emergency department the patient mentioned intermittent pre-cordial pain associated with exertion. At admission day she felt intense pre-cordial pain, accompanied by sudoresis and nausea, relieving with sublingual nitrate. The patient was hemodynamically stable at admission. Electrocardiogram showed sinus rhythm 65 bpm with 2mm ST-elevation of inferior leads. Troponin I was positive 30 ng/dL. Echocardiogram revealed marked hypokinesia of inferior and lateral wall with moderate depression of global systolic function ans presence of slight circumferential pericardial effusion (6mm in diastole on lateral wall)

Emergent coronariography was performed and revealed progression of coronary disease of the right coronary artery with sub-occlusion of the mid segment. Cardiac revascularization surgery was proposed and the patient accepted this time. Echocardiogram was repeated during hospitalization revealed a stable pericardial effusion with reduced dimension comparing to admission. After 3 weeks, while waiting surgery in the ward, the patient was a syncope that resulted in fracture of the distal peroneum. Ecocardiogram was performed and revealed a LV posterior wall pseudoaneurysm through a narrow neck in parasternal long axis view and the presence of large pericardial effusion (Fig 1). The patient was submitted to definitive reparative cardiac surgery with pericardium patch and coronary artery bypass graft from left internal mammary to anterior descending coronary artery. The patient recovered well from the cardiac surgery and at 2 months follow up is alive and without signs of heart failure.

This case illustrates the complexity in the management of patients with LV pseudoaneurysm. These patients require substantial critical care, imaging and surgical expertise.

A high clinical index of suspicion is needed to avoid missing the diagnosis LV pseudoaneurysm and transthoracic echocardiography is essential to establish the diagnosis.

Abstract P260 Figure. Fig 1 - LV pseudoaneurysm

P1722A new predictive score for mortality and cardiogenic shock in patients with ST-elevation myocardial infarction

Introduction

Acute Myocardial Infarction with ST elevation (STEMI) presents a high rate of potentially fatal complications and in-hospital mortality.

Objective

To test the predictive capacity for Cardiogenic Shock (CS) and In-hospital Mortality (MIH) of a new risk score in patients (Pts) with STEMI.

Population and methods

Evaluated 5765 Pts with STEMI without CS at admission. The new score, was derived by previous studies in this population, and was calculated according to the following criteria: age ≥65 years (1 point), heart rate ≥100bpm (2 points), systolic blood pressure <100mmHg (2 points), blood glucose at admission above 180 mg/dL (1 point) and creatinine at admission >1.5mg/dL (2 points). The population was divided into three subgroups: group A low score (0–2 points), group B intermediate score (3–5 points) and group C score (6–8 points). The endpoints defined were CS during hospitalization, in-hospital mortality and combined end-point of MIH and CS. The relationship between each of the possible scores (from 0 to 8) and the various end-points was determined, and the sensitivity and specificity of the score as a predictor of MIH and CS was defined as the area under the ROC curve (ASC).

Results

After the application of the score, 3 subgroups were obtained: group A with 4819 Pts (83,6%), group B with 884 Pts (15,3%) and group C 62 Pts (1,1%). Patients of group C had a higher MIH (Group C: 45,2% vs B: 11,4% vs A: 2,0%, p<0,001), higher CS (C: 29,5% vs B: 12,0% vs A: 2,3%, p<0,001) and a higher combined end-point of MIH and CC (C: 53,2% vs B: 17,8% vs A: 3,4%, p<0,001) during hospitalization. The proposed score revealed a high predictive capacity of MIH (ASC 0,802, 95% CI 0,775–0,830, p=0,001), of CS (ASC 0,763, 95% CI 0,731–0,795, p=0,001) and for the combined endpoint (MIH and CC) ASC 0,781, 95% CI 0,756–0,806, p=0,001). The logistic regression models showed that Pts with a high score (group C) presented a 41-fold higher risk of MIH (OR 41,3; p<0,001) and 18-fold higher CS (OR 18,0; p<0.001) than patients with low score (group A). It was also found that the risk associated with an increase in one point score unit was 100% (OR 2,0 p<0.001) for MIH and 82% (OR 1,82, p<0,001) for CS.

Conclusion

This new score, with the use of practical and friendly variables, demonstrated a high predictive capacity of MIH and CS.

P2265Cardiogenic shock without severe left ventricular dysfunction after ST-elevation acute myocardial infarction: population characterization and impact in prognosis

Background

The presence of cardiogenic shock (CS) after ST-elevation acute myocardial infarction (STEMI) is associated with a high mortality. Traditionally, severe left ventricular dysfunction is assumed to be the main predictor of CS, however trials and registries show that in average left ventricular function is only moderately depressed in CS after acute myocardial infarction.

Purpose

To characterize the population of patients (Pts) with CS after STEMI but without severe left ventricular dysfunction and assess their impact in mortality.

Methods

From a national multicenter registry, we evaluated 7181 Pts with STEMI and ejection fraction (EF) >30%, and excluded all pts with STEMI and an EF<30%. We considered 2 groups: Group 1 – Pts who developed CS and Group 2 - Pts who didn't developed CS. We registered age, gender, cardiovascular and non-cardiovascular co-morbidities, electrocardiographic presentation, vital signs at admission, reperfusion strategies, reperfusion times and coronary anatomy. We evaluated the following in-hospital complications: Re-Infarction, mechanical complications, high-grade atrial ventricular block, sustained ventricular tachycardia (VT) atrial fibrillation (AF) and stroke. We compared the in-hospital mortality.

Results

The presence of CS without severe left ventricular dysfunction was observed in 5,2% pts (n=376), being CS present at admission in 51,2% of these pts. The mean EF was lower in group 1 pts (44% ± 11 vs 51±11%, p<0,001). Patients in group 1 were older (70±14 vs 63±13 years, p<0,001), more females (39,4% vs 23,3%, p<0,001), had a higher prevalence of previous valvular heart disease (2,7% vs 1,0%, p=0,005), heart failure (4,8% vs 1,4%, p<0,001, peripheral artery disease (5,5% vs 2,9%, p=0,004), chronic kidney disease (6,4% vs 2,7%, p<0,001) and chronic pulmonary obstructive disease (8,2% vs 3,1%, p<0,001). At admission, Group 1 pts had more atrial fibrillation (10,4% vs 4,4%, p<0,001) and received less reperfusion (77,7% vs 83,0%, p=0,008), without differences in the type of reperfusion or times to reperfusion. The presence of multivessel disease (60,0% vs 45,7%, p<0,001) and left main disease (6,6% vs 2,4%, p<0,001) were more prevalent in Group 1 pts. Group 1 pts had more in-hospital complications: Re-Infarction (3,5% vs 0,7%, p<0,001), AF (22,1% vs 5,0%, p<0,001), mechanical complications (9,6% vs 0,5%, p<0,001), high atrial ventricular block (26,7% vs 3,7%, p<0,001), VT (10,6% vs 1,9%, p<0,001), stroke (1,9% vs 0,6%, p=0,01) and major bleeding (10,4% vs 1,5%, p<0,001). In-hospital mortality was much higher in Group 1 pts (26,6% vs 1,4%, p<0,001).

Conclusions

Cardiogenic shock is present in 5,2% of STEMI pts without severe ventricular dysfunction. These pts were older, more frequent female, had higher morbidities and in-hospital complications. Even without severe ventricular dysfunction, cardiogenic shock in these patients was associated with much higher in-hospital mortality.

P621Variation of global longitudinal strain (2D STE) with passive leg lifting maneuver: a marker of myocardial functional reserve?

Introduction

In a normal heart, the passive leg lifting maneuver (LLM) will result in an increase in myocardial contractility, according to the mechanistic concept of the Frank-Starling law. With the progression of myocardial disease this ability is impaired and the myocardial functional reserve (mFR) is reduced (Figure1 – Panel A). The variation of left ventricular global longitudinal strain (as an index of contractile function) with LLM may thus represent a marker of left ventricular mFR.

Purpose

To assess the variation of left ventricular global longitudinal strain (LV GLS) with LLM as a marker of mFR in a healthy population and in patients with myocardial disease (hypertrophic myocardiopathy - HCM and systolic dysfunction patients – SystDysf.

Methods and results

We evaluated the variation of LV GLS by 2-dimensional Speckle Tracking Echocardiography (2D-STE), in response to passive LLM, in a population of 103 individuals (54 healthy individuals, 28 HCM patients and 21 left ventricular SystDysf patients). Clinical, demographic and echocardiographic parameters (including LV longitudinal mechanics obtained with 2D-STE before and after LLM) were described. The population had a mean age of 46±18 years and 55% were women. Increased venous return to the heart during LLM was confirmed by an increase in the maximal diameter of the inferior vena cava (15,1±3,6 vs 20,6±3,8 mm, p<0.001).

There was a significant variation of LV GLS in healthy individuals submitted to LLM (−20,58±3,0 vs −21,5±2,6%, p=0,02, Δ 0,6%, 95% CI 0,1–1,1%). Regarding the HCM and SystDysf groups, no significant change in LV GLS was observed with LLM (−13,2±2,8 vs −12,3±2,9%, p=0,12, Δ +0,6%, 95% CI −1,4 to 0,18% and −10,2±2,5 vs 10,2±2,7%, p=0,79, Δ 0,08%, 95% CI −0,7 to 0,5%, respectively). Figure 1 (Panel B)

Conclusion

To our knowledge, this is the first report describing the use of LV GLS and LLM to assess mFR in this clinical setting. The absolute increase of LV GLS in the healthy population suggests that this may be a reliable method and a sensitive marker to assess the mFR. Conversely, patients with HCM and with SystDysf show poor or no response to the LLM, suggesting, as expected, a low myocardial functional reserve. Given the non-invasiveness and cost-effectiveness nature of this technique, we suggest that this maneuver could pose a feasible way to assess mFR. Further studies are needed to validate this technique and to assess the role of mFR by 2D-STE as a prognostic marker.

P1764Quality criteria for STEMI care - a national perspective

Introduction

The definition of quality criteria in health care is essential to implement structural organization strategies that ensure that patients (P) receive the best care according to the most updated recommendations available at the time they are treated. Quality indicators have recently been defined with regard to the approach and treatment of STEMI in the European Guidelines published in 2017.

Objective

The authors intend to characterize the level of care provided to P with STEMI inserted into a national multicenter registry since 2011 in order to establish a relationship with international recommendations.

Population and methods

Descriptive study based on a national multicenter registry. A total of 2051 P admitted to the hospital with the diagnosis of STEMI were included, 1266 P for the year 2011 and 785 P for the year 2016.

Results

The P of the year 2011 and 2016 presented similar age (64±14 vs 63±13). There was a higher percentage of P admitted by STEMI fast track managed care system in 2016 (36.9% vs 22.2%, p<0,001) and less from the Emergency Department (31.6% vs 56.8%; p<0,001). Regarding the transport to the Hospital, there was an increase in patients transported by prehospital medical teams (28% vs 21%; p<0,001) and less by own means (35.7% vs 45.6%; p<0,001). Regarding in-hospital therapy, it was found that in 2016 more patients received loading doses of P2Y12 inhibitors – Clopidogrel (78.1% vs 70.3% P<0,001) and Ticagrelor (54.7% vs 0.7% P<0,001). In post-discharge therapy, there was also a slight improvement in care in 2016, with more P being treated with P2Y12 inhibitor (96.2% vs 92.4%; p=0.03) and beta-blocker (84.4% vs 78.7%; p<0,001). Regarding the type of reperfusion, there was an increase in angioplasty (95.5% vs 92.2%; p<0,001) and a decrease in fibrinolysis (4.5% vs 7.8%; p=0.03) in 2016. There was a slight worsening of the prehospital delay in 2016 (median 163min vs 120min) and an improvement in door to reperfusion time (median 60min vs 70min). There was also an increase in angioplasties performed in 2016 (87.1% vs 85.1%; p<0,001) as well as an increase in the percentage of left ventricular function evaluation before discharge (98.2% vs 93.9%; p<0,001).

Conclusion

The results presented demonstrate a slight improvement in the quality of the care provided to STEMI P. However, there are areas for improvement, in accordance with international recommendations, in particular with regard to reperfusion times.

P309R' wave in precordial leads V1-V2 in patients from the young SCD-SOS cohort

Introduction

Sudden Cardiac Death – Screening Of risk factorS (SCD-SOS) survey aimed to screen for warning signs of potential channelopathies and cardiomyopathies that may course with sudden cardiac death in the young (≤40 years old) and consisted in an ECG and a digital-based previously validated questionnaire.

Purpose

We aimed to study clinical and electrocardiographic characteristics of young patients from the SCD-SOS cohort who presented with an r'-wave in precordial leads V1 and V2.

Methods

All the ECG were screened for the detection of an r'-wave in precordial leads V1 and V2. The ECGs selected were reviewed by a second investigator (agreed in 97.7% of the cases). We performed classical descriptive statistics and multivariate logistic regression to compare patients with and without r'-wave in these leads.

Results

From a total of 14669 patients who had an ECG performed as part of the SCD-SOS survey, 17% displayed an r'-wave in precordial leads V1 and V2 and 0.4% had complete right bundle branch block (RBBB). Patients with rSr' pattern had a mean age of 20±5 years old, 54% of them were male, they had a mean body mass index (BMI) of 22±3kg/m2, and 54% practiced sports regularly, with a mean of 5±4 hours of physical activity per week. Regarding previous symptoms reported by these individuals, 24% (n=487) reported a transient loss of consciousness, 15% (n=310) a reflex syncope, 3% (n=58) had unexplained syncope and 21% (n=425) palpitations. Sudden death in relatives before 50 years-old was present in 11% (n=172) of the patients with an r'-wave in V1-V2. After adjusting for heart rate and physical activity, PQ interval (OR 1.007 - CI95% 1.004–1.010, p<0.001), QTc interval (OR 1.009 - CI95% 1.005–1.012, p<0.001), male gender (OR 2.438 - CI95% 2.144–2.772, p<0.001) and BMI (OR 0.881 - CI95% 0.864–0.900, p<0.001) were independently associated with the presence of r'wave in precordial leads V1-V2. Unexplained syncope, palpitations and family history of sudden death were not associated with r'-wave in the young SCD-SOS population.

Conclusions

We conclude that r'-wave in V1-V2 is a frequent finding in the young population and that it is associated with higher PQ and QTc intervals. The prognostic implications of this pattern are unknown, but thorough differential diagnosis is warranted since this pattern may correspond to incomplete RBBB/athlete's ECG, and may also be suggestive of other potentially serious conditions such as Type 2 Brugada pattern and multiple causes of right ventricular enlargement. Finally, this pattern is also associated with male gender and lower BMI, suggesting a dependence on anatomical factors.

P1720Survival analysis in a population of patients with cardiogenic shock after acute myocardial infarction: characterization of the population and identification of mortality predictors

Introduction

The presence of cardiogenic shock (CC) after acute myocardial infarction (AMI) is associated with high mortality.

Purpose

To compare the clinical characteristics, cardiac and non-cardiac complications among survivors and non-survivors of CC after AMI in order to identify predictors of in-hospital mortality.

Population and methods

An observational study involving 467 patients (P) with CC after AMI included in a national multicenter registry. Considered 2 groups: Group 1 - P with CC who died (n=190) and Group 2 - P with CC who survived (n=277). We recorded age, gender, personal history, coronary angiography and angioplasty performed, in-hospital therapy and ejection fraction, cardiac complications (Re-infarction, mechanical complications, high-grade atrial ventricular block, sustained ventricular tachycardia) and non-cardiac complications [acute renal injury (ARI), major bleeding and stroke]. Multivariate analysis was performed to identify predictors of in-hospital mortality.

Results

Mortality in patients with CC after AMI was 40.6%. Group 1 P were older (77±10 vs 68±13 years, p<0.001), presented higher prevalence of diabetes mellitus (41.8% vs 28.2%, p=0.003), previous AMI (23.8% vs. 12%, p<0.001) 7%, p=0.002), previous angor (31.9% vs 14.1%, p=0.001), heart failure (18.6% vs 8.7%, p=0.002) and peripheral arterial disease (11.8% vs 6.2%, p=0.03). There were fewer coronary angiographies (64.2% vs 87.7%, p<0.001), with no difference in the number or type of vessels with lesions in both groups, as well as inotropic therapy. With the exception of mechanical complications, more prevalent in group 1 (12.6% vs 5.4%, p=0.006), there were no differences in the prevalence of the remaining cardiac complications. Among the non-cardiac complications considered, only the presence of ARI was more prevalent in Group 1 (72.1% vs 37.5%, p<0.001). After multivariate analysis the presence of age>75 years [OR: 2.21 (CI: 1.39–3.51)], previous angor [OR: 1.91 (CI: 1.09–2.92)], LRA [OR: 3.14 (CI: 4.0–7.04)] and mechanical complications [OR: 3.82 (CI: 2.39–6.10] were independent predictors of in-hospital mortality of P with CC post-AMI.

Conclusions

Mortality in patients with CC after AMI remains high. Age>75 years, prior angor, ARI and mechanical complications are independent predictors of in-hospital mortality in P with CC post-AMI.

P603Cardiac Magnetic Resonance evaluation and risk stratification of patients with unexplained or suspected arrhythmias

Introduction

The etiological diagnosis of cardiac arrhythmias is often difficult. Cardiac Magnetic Resonance (CMR) is the gold standard exam for anatomical and functional cardiac evaluation and it may be indicated in patients with ventricular arrhythmias when echocardiography does not provide an accurate assessment of left and right ventricles (LV, RV).

Purpose

The aim of this study was to determine the impact of CMR in the diagnosis and stratification of arrhythmic risk in patients with confirmed or suspected arrhythmias, as well as to describe the changes observed.

Methods

We performed a prospective registry over a 5-year period of all the patients with arrhythmias who underwent CMR for diagnostic and risk stratification purposes. We followed a protocol to evaluate both anatomically and functionally the ventricles and to look for the presence of late gadolinium enhancement (LGE).

Results

A total of 78 patients were included, of which 65% were male and a mean age of 46±17 years-old was observed. The indications for CMR evaluation of patients with confirmed or suspected arrhythmias were as follows: 33% (n=26) of the patients had very frequent premature ventricular complexes (PVC), 23% (n=18) had sustained ventricular tachycardia (VT), 17% (n=13) suspected structural heart disease with high arrhythmic potential, 12% (n=9) unexplained recurrent syncope, 6% (n=5) supraventricular tachycardia, 5% (n=4) non-sustained VT and 4% (n=3) aborted sudden cardiac death. Depressed ventricular ejection fraction (<50%) was present in 9% (n=7) for the LV and in 14% (n=11)for the RV. Dilation of the LV was found in 24% of the patients (n=19, mean LV volume: 115±4ml/m2) and RV dilation was present in only 1 patient who had right ventricle arrhythmogenic dysplasia (RVAD) (RV volume: 152ml/m2). Cardiac synchronization artifacts due to the presence of very frequent PVC compromised the calculation of v volumes in only 4% (n=3) of the patients. In total, 6% (n=5) had interventricular septum hypertrophy (mean 15±6g/m2), 10% (n=8) had a slight prolapse of the anterior leaflet of the mitral valve and 19% (n=15) had a dilated left auricle. LGE was present in 13% (n=10) and slight pericardium effusion was detected in 12% (n=9). CMR was considered normal in 65% (n=51), in 15% (n=12) we found nonspecific changes deserving follow-up and in 20% (n=15) it was possible to establish a diagnosis which was previously unknown: 5% (n=4) had hypertrophic cardiomyopathy, 4% (n=3) LV non-compaction, 4% (n=3) a myocarditis sequelae, 3% (n=2) RVAD, 3% (n=2) a myocardial infarction scar and 1 had non-ischemic dilated cardiomyopathy.

Conclusions

CMR is a technique with high spatial resolution, feasible and safe, which allowed an increase in diagnosis in 20% of the patients, thus contributing to the risk stratification of our study population with suspected high arrhythmic potential when the first-line complementary exams were inconclusive.

P4377Use of LV Deformation Imaging to predict long term Heart Failure Risk in high risk patients

Background

The increasing prevalence of heart failure (HF), due to hypertension, ischaemic heart disease, diabetes, obesity, and ageing population demands identification of at-risk subgroup whom we could target on prevention strategies. In a same cohort of patients at risk of HF (70% with CAD), 13% developed new HF hospitalization or death over 4.3 years of follow-up, however, disease management program did not confer any benefit to outcome and LV ejection fraction (EF) was not predictive of progression to HF. Better risk stratification strategies are needed. In this study, we sought whether advanced echo measure on deformation, global longitudinal strain (GLS) would predict HF admission over a long term follow up and thereby define an at-risk group. Aim: To determine which of the LV morphology, function and deformation parameters, best predict new HF admission or HF death in pts at risk but without prior dx of HF.

Method

Echocardiograms (including measurement of LV, size, function, morphology and deformation) were obtained in 431 inpatients (mean age 65±11, 72% male) at risk of HF. LV global longitudinal strain (GLS) and strain rate (GLSR) were measured offline (EchoPac, GE). Long term (9 years) follow up data were obtained via data linkage.

Results

63 pts (15%) reached the end-point of HF admission or HF death. LV deformation showed a univariable association with outcome (Table). In multivariable analysis, including known significant predictors of outcome (age, sex, BMI, diabetes, hypertension), GLS less than 18 remained an independent predictor (Table), in addition to age and DM at baseline. EF and LV mass were not predictors of heart failure.

HR (95% CI) P value HR (95% CI) P value HR (95% CI) P value Age 1.1 (1–1.1) <0.01 1.1 (1–1.1) 0.04 1 (1–1.1) 0.04 Sex 1.0 (0.6–1.7) 0.9 0.8 (0.4–1.8) 0.6 0.8 (0.4–1.8) 0.6 BMI 1.0 (1–1.1) 0.05 1 (0.9–1.1) 0.7 1 (0.9–1.1) 0.7 DM 2.6 (1.6–4.3) <0.01 2.7 (1.4–5.3) <0.01 2.7 (1.4–5.2) 0.04 LVMI 1.0 (1.0–1.0) <0.01 1 (0.9–1.0) 0.7 1 (0.99–1.0) 0.7 Impaired EF, % 1.0 (0.9–1.0) <0.01 1 (0.9–1.0) 0.16 0.97 (0.94–1.0) 0.04 Diastolic dysfunction 2.3 (1.4–3.7) <0.01 0.8 (0.3–1.7) 0.5 0.7 (0.3–1.7) 0.5 GLS 1.3 (1.4–1.2) <0.01 1.1 (1–1.2) 0.07 GLS <18 5.3 (2.8–10.2) <0.01 2.3 (1.1–5.1) 0.04

Conclusion

GLS <18 is independently associated with increasing new onset heart failure admission and HF mortality in patients at risk of HF.

Interaction of a dengue virus NS1-derived peptide with the inhibitory receptor KIR3DL1 on natural killer cells

Killer immunoglobulin-like receptors (KIRs) interact with human leucocyte antigen (HLA) class I ligands and play a key role in the regulation and activation of NK cells. The functional importance of KIR-HLA interactions has been demonstrated for a number of chronic viral infections, but to date only a few studies have been performed in the context of acute self-limited viral infections. During our investigation of CD8(+) T cell responses to a conserved HLA-B57-restricted epitope derived from dengue virus (DENV) non-structural protein-1 (NS1), we observed substantial binding of the tetrameric complex to non-T/non-B lymphocytes in peripheral blood mononuclear cells (PBMC) from a long-standing clinical cohort in Thailand. We confirmed binding of the NS1 tetramer to CD56(dim) NK cells, which are known to express KIRs. Using depletion studies and KIR-transfected cell lines, we demonstrated further that the NS1 tetramer bound the inhibitory receptor KIR3DL1. Phenotypical analysis of PBMC from HLA-B57(+) subjects with acute DENV infection revealed marked activation of NS1 tetramer-binding natural killer (NK) cells around the time of defervescence in subjects with severe dengue disease. Collectively, our findings indicate that subsets of NK cells are activated relatively late in the course of acute DENV illness and reveal a possible role for specific KIR-HLA interactions in the modulation of disease outcomes.