Sudden death predictors: an inflammatory association

Interplay Between Fitness, Systolic Blood Pressure and Sudden Cardiac Death (from a Cohort Study)

Modifiable risk factors, such as blood pressure and cardiorespiratory fitness (CRF) play a role in the genesis of sudden cardiac death (SCD). However, data on their joint contributions to SCD risk are scarce. We aimed to evaluate the interplay between systolic blood pressure (SBP), CRF, and SCD risk in a cohort of men. Resting SBP was measured using a random-zero sphygmomanometer and CRF was assessed using a respiratory gas exchange analyzer during clinical exercise testing at baseline in 2,291 men aged 42 to 61 years. SBP was classified as normal and high (<140 and ≥140 mm Hg, respectively) and CRF as low, medium, and high. Cox regression analysis was used to estimate hazard ratios (HRs) with 95% confidence intervals (CIs) for SCD. A total of 262 SCDs occurred during a median follow-up of 28.2 years. Comparing high versus normal SBP, the multivariable-adjusted HR (95% CI) for SCD was 1.35 (1.03 to 1.76). Comparing low versus high CRF levels, the corresponding adjusted HR (95% CI) for SCD was 1.81 (1.23 to 2.65). The HRs remained similar when SBP was further adjusted for CRF and CRF was further adjusted for SBP. Men with high SBP and low CRF compared with normal SBP and medium-high CRF, had an increased risk of SCD (HR 2.67, 95% CI 1.76 to 4.05), with no significant evidence of an association between men with high SBP and medium-high CRF and SCD risk (HR 1.38, 95% CI 0.84 to 2.26). There was modest evidence of an additive interaction between SBP and CRF in relation to SCD. In conclusion, there exists an interplay between SBP, CRF, and SCD risk in middle-aged and older men. Medium to high CRF levels may mitigate the increased risk of SCD in subjects with high SBP.

Haemodynamic Gain Index Is Associated with Risk of Sudden Cardiac Death and Improves Risk Prediction: A Cohort Study

INTRODUCTION

Haemodynamic gain index (HGI) is a novel haemodynamic parameter which can be obtained from cardiopulmonary exercise testing (CPX), but its association with sudden cardiac death (SCD) is not known. We aimed to assess the association of HGI with SCD risk in a long-term prospective cohort study.

METHODS

HGI was calculated using heart rate and systolic blood pressure (SBP) responses measured in 1897 men aged 42–61 years during CPX from rest to peak exercise. Cardiorespiratory fitness (CRF) was measured using respiratory gas exchange analysis. Multivariable adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) were estimated for SCD.

RESULTS

During a median follow-up of 28.7 years, 205 SCDs occurred. The risk of SCD decreased gradually with increasing HGI (p value for non-linearity = 0.63). A unit (bpm/mm Hg) higher HGI was associated with a decreased risk of SCD (HR: 0.84; 95% CI: 0.71-0.99), which was attenuated following adjustment for CRF. CRF was inversely associated with SCD, which remained after further adjustment for HGI (HR: 0.85; 95% CI: 0.77-0.94) per each unit higher CRF. Addition of HGI to a SCD risk prediction model containing established risk factors improved risk discrimination (C-index change = 0.0096; p = 0.017) and reclassification (net reclassification improvement [NRI] = 39.40%, p = 0.001). The corresponding values for CRF were (C-index change = 0.0178; p = 0.007) and (NRI = 43.79%, p = 0.001).

CONCLUSION

Higher HGI during CPX is associated with a lower SCD risk, consistent with a dose-response relationship but dependent on CRF levels. Though HGI significantly improves the prediction and classification of SCD beyond common cardiovascular risk factors, CRF remains a stronger risk indicator and predictor of SCD compared to HGI.

Cardiorespiratory Fitness, Inflammation, and Risk of Sudden Cardiac Death in Middle-Aged Men

Inflammation and cardiorespiratory fitness (CRF) are each independently related to the risk of sudden cardiac death (SCD). The interplay between CRF, inflammation and SCD is not well understood. We aimed to study the separate and joint associations of inflammation (high-sensitivity C-reactive protein [hsCRP]) and CRF with SCD risk in a cohort of Caucasian men. In 1,749 men aged 42 to 61 years without a history of coronary heart disease at baseline, serum hsCRP was measured using an immunometric assay, and CRF was assessed using a respiratory gas exchange analyzer during exercise testing. hsCRP was categorized as normal and high (≤3 and >3 mg/L, respectively) and CRF as low and high (median cutoff). A total of 148 SCD events occurred during a median follow-up of 28.9 years. Comparing high versus normal hsCRP, the multivariable-adjusted hazard ratio (95% confidence interval) for SCD was 1.65 (1.11 to 2.45), which remained similar on further adjustment for CRF 1.62 (1.09 to 2.40). Comparing high versus low CRF, the multivariable-adjusted hazard ratio for SCD was 0.61 (0.42 to 0.89), which remained persistent after adjustment for hsCRP 0.64 (0.44 to 0.93). Compared with normal hsCRP-low CRF, normal hsCRP-high CRF was associated with a decreased SCD risk of 0.65 (0.43 to 0.99), high hsCRP-low CRF was associated with an increased SCD risk of 1.72 (1.10 to 2.69), with no evidence of a relationship between high hsCRP-high CRF and SCD risk 0.86 (0.39 to 1.88). Positive additive and multiplicative interactions were found between hsCRP and CRF. In a middle-aged Finnish male population, both hsCRP and CRF are independently associated with SCD risk. However, high CRF levels appear to offset the increased SCD risk related to high hsCRP levels.

Targeting Inflammation in the Diagnosis, Management, and Prevention of Cardiovascular Diseases

Inflammation plays an important role in the development and progression of cardiovascular diseases (CVDs). Hypertension and hyperlipidemia are the key risk factors of CVDs and induce inflammation in the heart and vessels. Unhealthy diet, infection, and smoking coupled with genetic factors lead to the development of CVDs as well as induce inflammation. Risk factors of CVDs such as hypertension and hyperlipidemia along with diabetes activate nuclear factor kappa B, which regulates the transcription of immunoglobulin free light chain (FLC) κ in B cells and the production of multiple inflammatory molecules, leading to inflammation. FLCs are novel biomarkers of inflammation, and their levels have been associated with overall mortality in a general population and with cardiovascular outcomes. In this review, the role of inflammation in the pathogenesis of CVDs, new biomarkers of inflammation, and dietary options counterbalancing inflammatory processes, such as the polyphenol-rich French maritime pine bark extract Pycnogenol, are discussed.

Is sauna bathing protective of sudden cardiac death? A review of the evidence

Sudden cardiac death (SCD) is a global public health burden accounting for 15-20% of all deaths. Though established atherosclerotic risk factors explain a large proportion of the risk of SCD, these factors are often absent in a large proportion of SCD victims and the pathogenesis of SCD is still not fully established. It therefore appears that additional factors may be involved. Sauna bathing is a traditional Finnish activity that is mainly used for the purposes of relaxation and pleasure. Beyond its use for these purposes, sauna bathing has been linked with several health benefits. Emerging evidence suggests that sauna bathing is associated with reduced risk of adverse cardiovascular (CV) disease (CVD) and non-CVD outcomes as well as mortality. A number of reports have linked sauna bathing with reduced or increased risk of SCD, but the evidence is uncertain. This review summarizes available studies linking sauna bathing with SCD, the postulated mechanistic pathways underlying these associations, outlines areas of outstanding uncertainty, and the implications for prevention. We employed a comprehensive search for observational studies, randomized controlled trials (RCTs), and non-RCTs from MEDLINE and Embase since their inception until March 2019. Observational data suggest that regular sauna bathing is associated with a substantial risk reduction in SCD. Furthermore, the data suggest that a combination of regular physical activity and sauna baths confers substantial risk reduction for SCD compared with either modality alone. Few reports have linked sauna baths with SCDs, but these single case incidents have been attributed to the effects of dehydration, hypotension, and cardiac arrhythmias due to a combination of sauna exposure and alcohol consumption. Sauna bathing is generally safe for most healthy people and even among patients with stable CVD, if used sensibly and with caution. Plausible pathways underlying the protective effect of sauna bathing on SCD may be linked to the impact on CV function via reduced arterial stiffness, decreases in inflammation and oxidative stress, stabilization of the autonomic nervous system, beneficial changes in circulating lipid profiles and other CVD risk markers, and lowering of systemic blood pressure. Sauna is a potential novel tool to promote SCD prevention in addition to other known means, being an enjoyable way to take care of general health and well-being.

Lipoprotein(a) and risk of sudden cardiac death in middle-aged Finnish men: A new prospective cohort study

BACKGROUND

Lipoprotein(a) [Lp(a)] is an established and independent risk factor for cardiovascular outcomes. However, the relationship of Lp(a) with risk of sudden cardiac death (SCD) is unknown. We aimed to assess the association of Lp(a) with risk of SCD in the Kuopio Ischemic Heart Disease prospective cohort study of 1881 men aged 42-61years at recruitment.

METHODS AND RESULTS

Plasma Lp(a) concentration was assessed at baseline and repeat measurements made several years apart. After a median follow-up of 24.7years, 141 SCDs were recorded. Hazard ratios (HRs) (95% confidence intervals [CI]) were assessed and were corrected for within-person variability in Lp(a) levels. The regression dilution ratio of loge Lp(a) adjusted for age was 0.84 (95% CI: 0.81-0.88). Lipoprotein(a) levels were log-linearly associated with risk of SCD. In analyses adjusted for established risk factors, the HR (95% CI) for SCD per 1 standard deviation (3.56-fold) higher baseline loge Lp(a) was 1.24 (1.05-1.47; P=0.013). This remained consistent on further adjustment for alcohol consumption, resting heart rate, lipids, and C-reactive protein 1.23 (1.04-1.46; P=0.018). HRs remained unchanged after accounting for incident coronary events and did not vary importantly in several relevant clinical subgroups. Adding Lp(a) to a SCD risk prediction model did not significantly improve risk discrimination beyond established risk factors, but improved the continuous net reclassification 30.2% (1.1 to 59.2%, P=0.042).

CONCLUSIONS

Available evidence shows a continuous and independent association between Lp(a) levels and risk of SCD. Further research is needed to replicate these findings.

γ-Glutamyltransferase and Risk of Sudden Cardiac Death in Middle-Aged Finnish Men: A New Prospective Cohort Study

Background

γ‐Glutamyltransferase (GGT) has been linked to an increased risk of several cardiovascular outcomes; however, the relationship of GGT with sudden cardiac death (SCD) has not been investigated previously. We aimed to assess the association of GGT with risk of SCD.

Methods and Results

Serum GGT activity was assessed at baseline in the Kuopio Ischemic Heart Disease prospective cohort of 1780 men, and 136 SCDs were recorded during 22 years of follow‐up. Correction for within‐person variability was made using data from repeated measurements taken several years apart. The regression dilution ratio of log_eGGT adjusted for age was 0.68 (95% CI 0.61–0.74). Serum GGT was log‐linearly associated with risk of SCD. The hazard ratio for SCD per 1 SD higher baseline log_eGGT values (2‐fold higher) was 1.30 (95% CI 1.10–1.54; P=0.002) after adjustment for several established risk factors and remained consistent with further adjustment for alcohol consumption, resting heart rate, lipids, and C‐reactive protein (hazard ratio 1.26, 95% CI 1.05–1.50; P=0.014). The corresponding hazard ratios were 1.48 (95% CI 1.15–1.89; P=0.002) and 1.40 (95% CI 1.07–1.82; P=0.014) after correction for within‐person variability. Hazard ratios remained unchanged after accounting for incident coronary events and did not vary importantly by levels or categories of prespecified conventional risk factors.

Conclusions

GGT is positively, log‐linearly, and independently associated with future risk of SCD in the general male population. Further research is needed to replicate these findings.

Acute effects of outdoor air pollution on emergency department visits due to five clinical subtypes of coronary heart diseases in shanghai, china

BACKGROUND

Air pollution can be a contributing cause to the development and exacerbation of coronary heart disease (CHD), but there is little knowledge about the acute effects of air pollution on different clinical subtypes of CHD.

METHODS

We conducted a time-series study to investigate the association of air pollution (particulate matter with an aerodynamic diameter < 10 µm [PM10], sulfur dioxide [SO2], and nitrogen dioxide [NO2]) on emergency department (ED) visits due to five different subtypes of CHD in Shanghai, China, from 2010 to 2012. We applied an over-dispersed Poisson generalized addictive model to analyze the associations after controlling for the seasonality, day of the week, and weather conditions.

RESULTS

We identified a total of 47 523 ED visits for CHD. A 10-µg/m(3) increase in the present-day concentrations of PM10, SO2, and NO2 was associated with respective increases of 1.10% (95% confidence interval [CI] 0.33%-1.87%), 0.90% (95% CI -0.14%-1.93%), and 1.44% (95% CI 0.63%-2.26%) for total ED visits for CHD. These associations varied greatly by clinical type, with strong effects on sudden cardiac death, moderate effects on acute myocardial infarction and angina, weak effects on ischemic cardiomyopathy, and no effect on occult CHD. The associations were stronger among people aged 65 years or more than in younger individuals and in the cool season versus the warm one.

CONCLUSIONS

Outdoor air pollution may have different effects of air pollution on 5 subtypes of CHD. Our results might be useful for the primary prevention of various subtypes of CHD exacerbated by air pollution.

Rosuvastatin, inflammation, C-reactive protein, JUPITER, and primary prevention of cardiovascular disease--a perspective

The major public health concern worldwide is coronary heart disease, with dyslipidemia as a major risk factor. Statin drugs are recommended by several guidelines for both primary and secondary prevention. Rosuvastatin has been widely accepted because of its efficacy, potency, and superior safety profile. Inflammation is involved in all phases of atherosclerosis, with the process beginning in early youth and advancing relentlessly for decades throughout life. C-reactive protein (CRP) is a well-studied, nonspecific marker of inflammation which may reflect general health risk. Considerable evidence suggests CRP is an independent predictor of future cardiovascular events, but direct involvement in atherosclerosis remains controversial. Rosuvastatin is a synthetic, hydrophilic statin with unique stereochemistry. A large proportion of patients achieve evidence-based lipid targets while using the drug, and it slows progression and induces regression of atherosclerotic coronary lesions. Rosuvastatin lowers CRP levels significantly. The Justification for Use of statins in Prevention: an Intervention Trial Evaluating Rosuvastatin (JUPITER) trial was designed after the observation that when both low density lipoprotein and CRP were reduced, patients fared better than when only LDL was lowered. Advocates and critics alike acknowledge that the benefits of rosuvastatin in JUPITER were real. After a review, the US Food and Drug Administration extended the indications for rosuvastatin to include asymptomatic JUPITER-eligible individuals with one additional risk factor. The American Heart Association and Centers of Disease Control and Prevention had previously recognized the use of CRP in persons with "intermediate risk" as defined by global risk scores. The Canadian Cardiovascular Society guidelines went further and recommended use of statins in persons with low LDL and high CRP levels at intermediate risk. The JUPITER study focused attention on ostensibly healthy individuals with "normal" lipid profiles and high CRP values who benefited from statin therapy. The backdrop to JUPITER during this period was an increasing awareness of a rising cardiovascular risk burden and imperfect methods of risk evaluation, so that a significant number of individuals were being denied beneficial therapies. Other concerns have been a high level of residual risk in those who are treated, poor patient adherence, a need to follow guidelines more closely, a dual global epidemic of obesity and diabetes, and a progressively deteriorating level of physical activity in the population. Calls for new and more effective means of reducing risk for coronary heart disease are intensifying. In view of compelling evidence supporting earlier and aggressive therapy in people with high risk burdens, JUPITER simply offers another choice for stratification and earlier risk reduction in primary prevention patients. When indicated, and in individuals unwilling or unable to change their diet and lifestyles sufficiently, the benefits of statins greatly exceed the risks. Two side effects of interest are myotoxicity and an increase in the incidence of diabetes.

Neutrophil to lymphocyte ratio as a predictor of long-term mortality in African Americans undergoing percutaneous coronary intervention

BACKGROUND

Neutrophil to lymphocyte ratio (N/L ratio) has been shown to predict long-term mortality in patients undergoing percutaneous coronary intervention (PCI). African Americans have been shown to have lower mean neutrophil counts compared to whites. The usefulness of the N/L ratio in predicting long-term mortality in African Americans undergoing PCI is unknown.

METHODS

We evaluated a total of 372 African American patients (327 patients with lower N/L ratio [<3.5] and 45 patients with higher N/L ratio [> or =3.5]) who underwent PCI during January 2003 to August 2005. The primary endpoint was all-cause mortality at a median follow-up to 3.6 years.

RESULTS

During the median ( +/- SD) follow-up period of 3.6 +/- 1 years, there were a total of 48 deaths. The mortality rate was 10.4% in the group with a lower N/L ratio and 31.1% in the group with a higher N/L ratio (unadjusted p < 0.001). After adjustment for covariates with significant impact on mortality, N/L ratio was still a strong and independent predictor of long-term mortality with a hazard ratio (HR) of 2.1 (95% confidence interval [CI]: 1.1-4; p = 0.02). N/L ratio was also found to be a strong and independent predictor of long-term mortality even when analyzed as a categorical variable with 3 groups (HR of 0.39 for lower tertile compared to the upper tertile, 95% CI: 0.19-0.81; p = 0.012) and as a continuous variable (p = 0.002).

CONCLUSION

N/L ratio is a powerful independent predictor of long-term mortality in African Americans undergoing PCI.

Role of proinflammatory markers and NT-proBNP in patients with an implantable cardioverter-defibrillator and an electrical storm

BACKGROUND

Several studies have attempted to identify risk factors for the development of an electrical storm (ES), which is defined as 3 separate ventricular tachyarrhythmic (VT/VF) events, but in the majority of studies no triggers have been found. However, little is known about the role of inflammation and NT-proBNP in patients with ES. The aim of this study was therefore to assess the relationship of Interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and NT-proBNP serum concentrations in ICD-patients with or without single spontaneous ventricular tachyarrhythmic events (VT/VF) and in ES.

METHODS

Markers were determined in 51 patients without ICD-intervention, in 15 ICD-patients with single VT/VF-episodes during 9-months follow-up and in 20 ICD-patients with ES (blood sampling performed within 60min after fulfilling ES criteria). VT/VF-episodes were analysed by stored ICD-electrograms.

RESULTS

All patients had idiopathic dilated cardiomyopathy (n=23) or coronary artery disease (n=63). Patients with ES revealed significantly higher mean serum concentrations of all markers (IL-6 15.19+/-10.34 pg/mL, hs-CRP 20.12+/-14.4 mg/L, NT-proBNP 4799+/-4596 pg/mL) compared to baseline values of patients with single VT/VF-events during follow-up (IL-6 8.37+/-5.8 pg/mL (p=0.03), hs-CRP 4.7+/-5.3 mg/dL (p<0.001), NT-proBNP 1913+/-2665pg/mL (p=0.04)) and compared to baseline values of ICD-patients without device intervention (IL-6 4.62+/-3.66 pg/mL (p<0.001), hs-CRP 4.1+/-3.4 mg/L (p<0.001), NT-proBNP 1461+/-2281pg/mL (p<0.001)). In 9/20 patients presenting with ES (45%) baseline values were available. All markers were significantly higher during ES compared to event-free determination (IL-6 14.54+/-10.43 vs. 7.03+/-2.83 pg/mL (p=0.04), hs-CRP 19.07+/-16.07 vs. 6.5+/-3.9 mg/L (p=0.02), NT-proBNP 4218+/-2561 vs. 2099+/-1279 pg/mL (p=0.03)).

CONCLUSIONS

Electrical storm is associated with significantly elevated IL-6, hs-CRP and NT-proBNP serum concentrations in ICD-patients with structural heart disease. Thus, ES may be triggered by proinflammatory activity. Combined intraindividual elevation of determined markers might help to identify patients at risk of impending electrical storm.

Prospective study of interleukin-6 and the risk of malignant ventricular tachyarrhythmia in ICD-recipients—A pilot study

OBJECTIVE

We investigated the relationship between interleukin-6 (IL-6) and the risk of experiencing spontaneous ventricular tachyarrhythmia (VT/VF) in patients with an implantable cardioverter-defibrillator (ICD).

BACKGROUND

Cytokine levels predict outcome in patients with advanced heart failure and are elevated in patients with coronary artery disease (CAD). Regarding heart rhythm disturbances, proinflammatory activity could predict the occurrence of atrial fibrillation. There is no data on cytokine levels and the risk of spontaneous VT/VF.

METHODS

IL-6 serum concentrations were determined at baseline and follow-up in 47 consecutive ICD-patients with CAD and idiopathic dilated cardiomyopathy (IDC). Data were prospectively correlated with VT/VF-incidence.

RESULTS

Thirty-six patients (76.6%) suffered from CAD and 11 (23.4%) from IDC. Mean serum concentrations of IL-6 at baseline and at 9 months follow-up were 6.12+/-4.98 and 4.63+/-6.97. 88 spontaneous VT/VF-events occurred in 13/47 patients (27.7%). Patients with VT/VF had significantly higher IL-6 levels as compared to patients without VT/VF (8.96+/-5.97 vs. 5.04+/-4.16pg/ml at baseline (p =0.03), 7.8+/-4.88 vs. 3.42+/-6.32pg/ml at follow-up (p =0.01)).

CONCLUSIONS

Elevated IL-6 serum concentrations were prospectively associated with an increased risk of spontaneous VT/VF-events in ICD-patients with CAD or IDC. These preliminary findings support a possible association of proinflammatory activity and an increased susceptibility to spontaneous VT/VF-events.

Risk factors for out-of-hospital cardiac arrest: the Reykjavik Study

AIMS

To examine risk factors for out-of-hospital cardiac arrest in the Reykjavik Study, a long-term, prospective, population-based cohort study that started in 1967.

METHODS AND RESULTS

From 1987 to 1996, 137 men and 44 women out of the 8006 men and 9435 women in the study sustained out-of-hospital cardiac arrest due to cardiac causes. Determinants included coronary artery disease (CAD), its classical risk factors, and age, body mass index (BMI), heart rate, cardiomegaly, and erythrocyte sedimentation rate. Electrocardiograms (ECGs) were examined for various abnormalities. Significance was determined by Cox regression analysis. In multivariable analysis, the risk in men was significantly associated with age, diastolic blood pressure, cholesterol, current smoking, and previous diagnosis of myocardial infarction (MI). In women, the risk was associated with diastolic blood pressure, elevated levels of cholesterol and triglycerides, and increased voltage on ECG. Increased BMI was inversely related to women's risk of out-of-hospital cardiac arrest.

CONCLUSION

In this prospective, population-based cohort study previous MI and the classical risk factors for CAD significantly increased the risk of out-of-hospital cardiac arrest, the endpoint of this study. Increased voltage on ECG additionally increased women's risk.

Risk stratification and management of sudden cardiac death: a new paradigm

Risk Stratification and Management of SCD. Management of SCD is undergoing radical change in direction. It is becoming increasingly appreciated that besides depressed left ventricular systolic function and the conventional risk stratification tools, new markers for plaque vulnerability, enhanced thrombogenesis, specific genetic alterations of the autonomic nervous system, cardiac sarcolemmal and contractile proteins, and familial clustering may better segregate patients with atherosclerotic coronary artery disease who are at high risk for SCD from those who may suffer from nonfatal ischemic events. Better understanding of pathophysiologic processes, such as postmyocardial infarction remodeling, the transition from compensated hypertrophy to heart failure, and the increased cardiovascular risk of coronary artery disease in the presence of diabetes or even a prediabetic state will help to improve both risk stratification and management. The rapidly developing fields of microchips technology and proteomics may allow rapid and cost-effective mass screening of multiple risk factors for SCD. The ultimate goal is to identify novel methods for risk stratification, risk modification, and prevention of SCD that could be applied to the general public at large.

Anti-inflammatory therapy for heart failure

Recently, inflammation has been shown to be an important aspect of cardiovascular diseases, and markers of inflammation predict risk of adverse cardiovascular events. Accumulating evidence shows that heart failure is an inflammatory disease, and anti-inflammatory therapy by various agents would be a promising future treatment for heart failure.

Impact of preprocedural white blood cell count on long term mortality after percutaneous coronary intervention: insights from the EPIC, EPILOG, and EPISTENT trials

BACKGROUND

Raised inflammatory markers are associated with worse outcome after percutaneous coronary interventions (PCI). An increase in the white blood cell (WBC) count is a non-specific response to inflammation. We hypothesised that a raised baseline WBC count would be a predictor of mortality in patients undergoing PCI.

METHODS

The association between preprocedural WBC count and long term mortality was studied in 7179 patients enrolled in the EPIC, EPILOG, and EPISTENT trials. The end points were the incidence of myocardial infarction at one year, and one and three year mortality.

RESULTS

There were 188 deaths and 582 myocardial infarctions at one year. While WBC count was a strong predictor of death at one year, with every increase of 1 k/micro l (1x10(6)/l) being associated with a hazard ratio (HR) of 1.109 (95% confidence interval (CI) 1.072 to 1.147, p < 0.001), there was no association with myocardial infarction at one year (HR 1.020, 95% CI 0.990 to 1.052, p = 0.195). There were a total of 406 deaths at three years with a strong association between WBC count and three year mortality (HR for every 1 k/microl increase 1.089, 95% CI 1.058 to 1.121, p < 0.001). WBC count remained a significant predictor of mortality after multivariable adjustment (HR for every 1 k/micro l increase 1.100, 95% CI 1.069 to 1.131, p < 0.001). The association was significant across multiple subgroups, including diabetes, female sex, clinical presentation, and cigarette smoking.

CONCLUSION

A raised pre-procedural WBC count in patients undergoing PCI is associated with an increased risk of long term death. These results suggest a key role for inflammation in coronary artery disease.