POS0956 HIGH INFLAMMATORY BURDEN PREDICTS CARDIOVASCULAR EVENTS IN PATIENTS WITH AXIAL SPONDYLOARTHRITIS: A LONG-TERM FOLLOW-UP STUDY

Background

Axial spondyloarthritis (axSpA) patients had a higher risk of cardiovascular disease (CVD) than the general population (1). It is also suggested that inflammation, rather than a particular disease, drives the increased risk of CVD (2). But the relationship between inflammation in axSpA and CVD is unknown.

Objectives

To examine whether inflammatory burden over time can predict cardiovascular events (CVE) independent of baseline CV risk factors in axial spondyloarthritis (axSpA) patients.

Methods

A cohort analysis was performed in patients who had been recruited since January 2001. The primary outcome was a first CVE occurring between January 2001 and December 2020. Three CVD risk scores were computed at baseline. The performance of the original and modified (x 1.5 multiplication factor) CV risk algorithms were assessed. Time-varying Cox proportional hazard models and Kaplan-Meier survival analysis were used to assess whether inflammatory burden (Bath ankylosing spondylitis disease activity index [BASDAI] and inflammatory markers), non-steroidal anti-inflammatory drugs (NSAIDs) and disease modifying anti-rheumatic drugs (DMARDs) can predict the development of first CVE.

Results

463 patients [35(26-45) years, male: 360(77.8%)] were recruited. After a median follow up of 12 (7-19) years, 61 patients (13.2%) experienced a first CVE. Traditional/modified CV risk scores underestimated CV risk. Erythrocyte sedimentation rate (ESR)≥20 mm/hr was associated with a significantly higher risk of CVE during follow-up [HR: 2.07, 95%CI (1.10, 3.98), p=0.008]. Active disease as indicated by a rising BASDAI also showed positive trend towards a higher risk of developing CVE over time. After adjusting for CV risk scores in the multivariable models, high ESR level (ESR≥20 mm/hr) over time remained significantly associated with a higher risk of developing CV events (Table 1a and 1b). A significant difference in the CV event-free survival between patients with ESR≥20 mm/hr and ESR<20 mm/hr was demonstrated in Figure 1.

Table 1.

Multivariable analysis with time-dependent Cox proportional hazard regression for the predictors of cardiovascular events.

Figure 1.

Kaplan-Meier survival analysis between time-varying ESR level and CVE. P=0.006 for difference in CVE-free survival rate between patients with ESR≥20mm/hr and ESR<20mm/hr during their follow-up intervals. ESR: Erythrocyte Sedimentation Rate.

Conclusion

Increased inflammatory burden as reflected by elevated ESR levels (ESR≥20) was associated with increased risk of CVE, while the use of NSAIDs and DMARDs were not.

References

[1]Exarchou, S., et al., Mortality in ankylosing spondylitis: results from a nationwide population-based study. Ann Rheum Dis, 2016. 75(8): p. 1466-72.

[2]Lauper, K., et al., Incidence and Prevalence of Major Adverse Cardiovascular Events in Rheumatoid Arthritis, Psoriatic Arthritis, and Axial Spondyloarthritis. Arthritis Care & Research, 2018. 70(12): p. 1756-1763.

Table 1a.Model 1Model 2Model 3Time-dependent HR (95%CI)p-valueTime-dependent HR (95%CI)P-valueTime-dependent HR (95%CI)P-valueESR≥202.75 (1.23, 6.14)0.014*2.74 (1.21, 6.21)0.016*2.93 (1.31, 6.57)0.009*BASDAI1.07 (0.90, 1.28)0.4551.06 (0.88, 1.28)0.5191.07 (0.89, 1.28)0.442FRS1.06 (1.03, 1.09)<0.001*QRISK31.05 (0.99, 1.11)0.132SCORE1.25 (1.09, 1.42)0.001*Table 1b.Model 1Model 2Model 3Time-dependent HR (95%CI)P-valueTime-dependent HR (95%CI)P-valueTime-dependent HR (95%CI)P-valueESR≥202.77 (1.24, 6.18)0.013*2.78 (1.23, 6.28)0.014*2.95 (1.32, 6.59)0.008*BASDAI≥41.37 (0.62, 2.99)0.4341.26 (0.58, 2.78)0.5591.42 (0.65, 3.09)0.376FRS1.06 (1.03, 1.09)<0.001*QRISK31.05 (0.99, 1.11)0.138SCORE1.24 (1.09, 1.42)0.001*

*Statistically significant at p≤0.05.

HR, hazard ratio; BASDAI: Bath Ankylosing Spondylitis Disease Activity Index; CRP: C-Reactive Protein; ESR: Erythrocyte Sedimentation Rate; FRS: Framingham Risk Score; SCORE: Systematic Coronary Risk Evaluation.

Acknowledgements

We would like to show our gratitude to all medical staffs, research assistants.

Disclosure of Interests

None declared

POS0323 RISK FACTORS FOR MAJOR CARDIOVASCULAR EVENTS (MACE) IN INFLAMMATORY ARTHRITIS: A TIME-DEPENDENT ANALYSIS ON INFLAMMATORY BURDEN, USE OF NSAIDs, STEROID AND DMARDs

Background

Inflammatory arthritis (IA) including rheumatoid arthritis (RA), psoriatic arthritis (PsA) and ankylosing spondylarthritis (AS) are associated with accelerated atherosclerosis due to systematic inflammation.

Objectives

To elucidate whether inflammatory burden (c-reactive protein [CRP] and erythrocyte sedimentation rate [ESR] levels) and drugs used to suppress inflammation (disease modifying anti-rheumatic drugs [DMARDs] and non-steroidal anti-inflammatory drugs [NSAIDs]) over time are independently associated with major cardiovascular events (MACE) in patients with IA.

Methods

A population-based cohort of IA patients were identified in the citywide Clinical Data Analysis and Reporting System (CDARS) of the Hong Kong Hospital Authority. IA patients recruited from 2006 to 2016 were followed until the end of 2018. The outcome was occurrence of a first MACE, defined as unstable angina, acute myocardial infarction, stroke/transient ischemic attack or death from cardiovascular causes. Cox proportional hazard models with time-varying CRP and ESR levels and drugs used were analyzed to identify the risk of having MACE in IA patients.

Results

A total of 17,732 (12050 RA patients, 1789 PsA patients and 3893 AS patients) patients with IA were recruited. After a mean follow-up of 8.7 ± 3.1 years, 1,069 (6.0 %) patients developed a first MACE. At baseline, the MACE group were older (68±12 vs 53±15, p<0.001), had more traditional cardiovascular risk factors, higher levels of CRP (2.7±1.5 vs 1.7±1.3, p<0.001) and ESR (57.8±32.4 vs 42.5±29.2, p<0.001), and less exposure to biologic DMARDs (bDMARDs) (1.0% vs 3.0%, p<0.001) and non-selective NSAIDs (nsNSAIDs) (63.4% vs 71.1%, p<0.001). After adjusting for age, sex, baseline cardiovascular comorbidities using multivariable Cox regression analysis, IA patients with higher inflammatory burden (as reflected by the time-varying CRP [hazard ratio {HR} 1.11, 95% confidence interval {CI} 1.10-1.12, p<0.001] and ESR levels (HR 1.02, 95% CI 1.01-1.01, p<0.001) and the use of steroid (HR 1.79-1.88) were independently associated with a higher risk of developing MACE (Table 1). In contrast, exposure to nsNSAIDs had a protective effect against MACE (HR 0.76, 95% CI 0.66-0.89, p<0.001), while bDMARDs were not associated with MACE.

Table 1.

Multivariable time-varying Cox regression models for the predictors of incidence of MACE in the IA patients (n=17732)

Model 1 †Model 2 ‡VariablesHR (95% CI)p valueHR (95% CI)p valueMale1.92 (1.65-2.23)<0.001*1.52 (1.33-1.76)<0.001*Age1.06 (1.05-1.06)<0.001*1.06 (1.05-1.06)<0.001*Disease duration1.04 (0.97-1.08)0.0561.04 (1.01-1.08)0.016*Baseline DM1.25 (0.95-1.64)0.1081.44 (1.13-1.84)0.003*Baseline HT1.77 (1.52-2.08)<0.001*1.85 (1.59-2.16)<0.001*Baseline LP1.14 (0.92-1.41)0.2321.19 (0.98-1.46)0.081Time-varying inflammatory markersESR1.02 (1.01-1.01)<0.001*CRP1.11 (1.10-1.12)<0.001*Time-varying treatmentbDMARDs0.93 (0.68-1.27)0.6570.89 (0.65-1.22)0.478CoxII0.71 (0.53-0.96)0.027*0.79 (0.59-1.04)0.104nsNSAIDs0.76 (0.66-0.89)<0.001*0.76 (0.66-0.88)<0.001*Steroids1.88 (1.63-2.17)<0.001*1.79(1.56-2.04)<0.001*

*Statistically significant at p < 0.05.

† and ‡ Adjusted for Age, Sex, Hypertension at baseline, diabetes mellitus at baseline, dyslipidemia at baseline, bDMARDs, CoxII, non-selective NSAIDs, Steroids.

CRP, C-reactive protein; ESR: Erythrocyte sedimentation rate; HT: hypertension; DM: diabetes mellitus; LP: Dyslipidemia; bDMARD, biological disease-modifying anti-rheumatic drug; COXII: cyclooxygenase -2 inhibitors; nsNSAIDs: non-selective nonsteroidal anti-inflammatory drugs.

Conclusion

Increased inflammatory burden as reflected by elevated ESR and CRP level over time, and increased exposure to steroid were independently associated with increased risk of MACE, while the risk was significantly reduced with non-selective NSAIDs use in IA patients.

Disclosure of Interests

None declared

POS1079 ASSOCIATION OF C-REACTIVE PROTEIN AND NON-STEROIDAL ANTI-INFLAMMATORY DRUGS WITH CARDIOVASCULAR EVENTS IN PATIENTS WITH PSORIATIC ARTHRITIS: A TIME-DEPENDENT Cox REGRESSION ANALYSIS

Background:

Psoriatic arthritis (PsA) is associated with accelerated atherosclerosis due to underlying inflammation. Whether inflammatory burden and drugs used to suppress inflammation over time are associated with cardiovascular (CV) events remains unclear.

Objectives:

This study aims to examine the time-varying effect of C-reactive protein (CRP) levels and the use of drugs including non-steroidal anti-inflammatory drugs (NSAIDs) on the risk of CV events independent of traditional CV risk factors in PsA patients.

Methods:

A retrospective cohort analysis was performed in patients with PsA who were recruited from 2008 to 2015 and followed till the end of 2019. The outcome was occurrence of a first CV event. Framingham risk score (FRS) was used to quantify the traditional CV risk. Cox proportional hazard models with time-varying CRP levels and drugs used were analyzed to identify the risk factors for CV events in PsA patients.

Results:

200 patients with PsA (median age: 47.5[40.0 – 56.0]; male: 119 [59.5%]) were recruited (Table 1. next page). After a mean follow-up of 8.8±3.8 years, 30 (15%) patients developed a first CV event. The Kaplan-Meier survival analysis indicated a significant difference in the CV event-free survival between patients with and without CRP level >3 mg/L (Figure 1A) and an inverse relationship between time-varying NSAIDs exposure and CV event-free survival (Figure 1B). The multivariable Cox regression model showed that time-varying CRP level (HR 1.02, 95% CI 1.00 to 1.04) and NSAIDs exposure (HR 0.30, 95% CI 0.15 to 0.95) were significantly associated with CV events after adjusting for baseline FRS (HR 5.04, 95% CI 1.83 to 13.85).

Table 1.

Baseline demographic and clinical characteristics, cardiovascular risk factors and treatments received.

VariablesAll patientsn=200median (IQR) or n (%)CVD -ve,n=170median (IQR)or n (%)CVD +ve,n=30median (IQR)or n (%)p-valueNSAID -ve, n=61median (IQR)or n (%)NSAID +ve, n=139median (IQR) or n (%)p-valueMale, n (%)119 (59.5%)100 (58.6%)19 (63.3%)0.22839 (63.9%)80 (57.6%)0.397Age, years47.5 (40.0 – 56.0)46.5 (37.7 – 54.0)57.0 (45.3 – 65.8)<0.001*49.0 (44.0 – 56.5)46.0 (38.0 – 54.8)0.176Disease duration, years4.3 (1.8 – 7.9)4.1 (1.7 – 7.0)6.0 (2.1 – 8.6)0.0664.6 (1.5 – 8.7)4.3 (1.9 – 7.3)0.393Diabetes, n (%)45 (22.5%)30 (17.6%)15 (50.0%)<0.001*10 (16.4%)35 (25.2%)0.171Hypertension, n (%)68 (34.0%)46 (27.1%)22 (73.3%)<0.001*21 (34.4%)47 (33.9%)0.933CRP, mg/L4.9 (1.7 – 12.6)4.2 (1.5 – 12.0)11.3 (2.4 – 19.6)0.035*5.5 (1.7 – 15.1)7.2 (1.4 – 15.8)0.770ESR, mm/hr21 (10.0 – 38.0)20 (9 – 35)31 (14 – 60)0.038*21 (7 – 33)21 (11 – 43)0.291Systolic blood pressure, mmHg125 (115 – 140)124 (115 – 137)144 (129 – 160)<0.001*123 (118 – 137)125 (115 – 141)0.889Diastolic blood pressure, mmHg78 (70 – 85)78 (70 – 84)82 (72 – 90)0.19978 (72 – 86)78 (70 – 85)0.697FRS8.4 (4.0 – 17.0)7.5 (3.3 – 14.0)19.6 (13.4 – 43.0)<0.001*7.9 (3.5 – 15.5)8.7 (4.2 – 17.1)0.885Lipid-lowering drugs, n (%)30 (15.0%)25 (14.7%)5 (16.7%)0.7829 (14.8%)21 (15.1%)0.949MTX, n (%)99 (49.5%)81 (47.6%)18 (60.0%)0.21225 (41.0%)74 (53.2%)0.111bDMARDs, n (%)17 (8.5%)13 (7.6%)4 (13.3%)0.3036 (9.8%)11 (7.9%)0.654NSAIDs, n (%)139 (69.2%)119 (70.0%)20 (66.7%)0.715N/AN/AN/ASteroid, n (%)2 (1.0%)2 (1.2%)0 (0%)1.0001 (1.6%)1 (0.7%)0.518

*statistically significant at p≤ 0.05

CVD+ve, patients who developed cardiovascular events during subsequent follow-up;

CVD-ve, patients who did not developed cardiovascular events during subsequent follow-up;

NSAIDs, nonsteroidal anti-inflammatory drugs; CRP, C-reactive protein; ESR, erythrocyte sedimentation rate; FRS, Framingham Risk Score; MTX, methotrexate; bDMARDs, biological disease-modifying antirheumatic drugs.

Conclusion:

Increased inflammatory burden as reflected by elevated CRP level was associated with increased risk of CV events, while the risk was significantly reduced with NSAIDs use in PsA patients.

Disclosure of Interests:

None declared.

Comparison of bone structure and microstructure in the metacarpal heads between patients with psoriatic arthritis and healthy controls: an HR-pQCT study

Human cadaveric study has indicated that the metacarpal head (MCH) is intracapsular in location. We hypothesized that exposure to the intra-articular inflammatory milieu in psoriatic arthritis (PsA) will lead to bone loss in the MCH.

INTRODUCTION

To compare the bone structure and microstructure in the MCH between patients with PsA and healthy controls by high-resolution peripheral quantitative CT (HR-pQCT), and to ascertain factors associated with bone loss in PsA patients.

METHODS

Sixty-two PsA patients without joint destruction and 62 age-, gender-, and body mass index-matched healthy subjects underwent HR-pQCT imaging of the second and third MCH (MCH 2&3). The number and volume of bone erosion and enthesiophytes, as well as volumetric bone mineral density (vBMD) and microstructure at the MCH 2&3, were recorded. Correlation analysis and multivariable linear regression models were used to determine the association of demographic and disease-specific variables with compromised bone structure and microstructure in PsA.

RESULTS

At the MCH 2&3, bone erosion (p = 0.003) and enthesiophyte (p = 0.000) volumes in PsA patients were significantly larger than healthy controls. In PsA patients, older age was associated with a larger erosion and enthesiophyte volume. Concerning the mean vBMD and microstructure at the MCH 2&3, PsA patients had significantly lower mean vBMD (average vBMD - 6.9%, trabecular vBMD - 8.8%, peri-trabecular vBMD - 7.7%, meta-trabecular vBMD - 9.8%), trabecular bone volume fraction (- 8.8%), and trabecular thickness (- 8.1%) compared with control subjects. Multivariable regression analysis revealed that older age and a higher C-reactive protein level were associated with trabecular bone loss.

CONCLUSIONS

PsA patients had a higher burden of bone damages (erosions and enthesiophytes) and trabecular bone loss compared with healthy control at the MCH. Inflammation contributed to the deterioration in trabecular microstructure in these patients.

Tropospheric volatile organic compounds in China

Photochemical smog, characterized by high concentrations of ozone (O₃) and fine particles (PM_2.5) in the atmosphere, has become one of the top environmental concerns in China. Volatile organic compounds (VOCs), one of the key precursors of O₃ and secondary organic aerosol (SOA) (an important component of PM_2.5), have a critical influence on atmospheric chemistry and subsequently affect regional and global climate. Thus, VOCs have been extensively studied in many cities and regions in China, especially in the North China Plain, the Yangtze River Delta and the Pearl River Delta regions where photochemical smog pollution has become increasingly worse over recent decades. This paper reviews the main studies conducted in China on the characteristics and sources of VOCs, their relationship with O₃ and SOA, and their removal technology. This paper also provides an integrated literature review on the formulation and implementation of effective control strategies of VOCs and photochemical smog, as well as suggestions for future directions of VOCs study in China.

Evaluation of the effectiveness of air pollution control measures in Hong Kong

From 2005 to 2013, volatile organic compounds (VOCs) and other trace gases were continuously measured at a suburban site in Hong Kong. The measurement data showed that the concentrations of most air pollutants decreased during these years. However, ozone (O₃) and total non-methane hydrocarbon levels increased with the rate of 0.23 ± 0.03 and 0.34 ± 0.02 ppbv/year, respectively, pointing to the increasing severity of photochemical pollution in Hong Kong. The Hong Kong government has ongoing programs to improve air quality in Hong Kong, including a solvent program implemented during 2007-2011, and a diesel commercial vehicle (DCV) program since 2007. From before to after the solvent program, the sum of toluene, ethylbenzene and xylene isomers decreased continuously with an average rate of -99.1 ± 6.9 pptv/year, whereas the sum of ethene and propene increased by 48.2 ± 2.0 pptv/year from before to during the DCV program. Despite this, source apportionment results showed that VOCs emitted from diesel exhaust decreased at a rate of -304.5 ± 17.7 pptv/year, while solvent related VOCs decreased at a rate of -204.7 ± 39.7 pptv/year. The gasoline and liquefied petroleum gas vehicle emissions elevated by 1086 ± 34 pptv/year, and were responsible for the increases of ethene and propene. Overall, the simulated O₃ rate of increase was lowered from 0.39 ± 0.03 to 0.16 ± 0.05 ppbv/year by the solvent and DCV programs, because O₃ produced by solvent usage and diesel exhaust related VOCs decreased (p < 0.05) by 0.16 ± 0.01 and 0.05 ± 0.01 ppbv/year between 2005 and 2013, respectively. However, enhanced VOC emissions from gasoline and LPG vehicles accounted for most of the O₃ increment (0.09 ± 0.01 out of 0.16 ± 0.05 ppbv/year) in these years. To maintain a zero O₃ increment in 2020 relative to 2010, the lowest reduction ratio of VOCs/NOx was ∼1.5 under the NOx reduction of 20-30% which was based on the emission reduction plan for Pearl River Delta region in 2020.

On the relationship between ozone and its precursors in the Pearl River Delta: application of an observation-based model (OBM)

BACKGROUND, AIM, AND SCOPE

Photochemical smog, characterized by high concentrations of O(3) and fine particles, is of great concern in the urban areas, in particular megacities and city clusters like the Pearl River Delta.

MATERIALS, METHODS, AND RESULTS

Ambient ozone (O(3)) and its precursors were simultaneously measured at two sites in the Pearl River Delta, namely, Wan Qing Sha (WQS) in Guangzhou and Tung Chung (TC) in Hong Kong, from 23 October to 01 December 2007 in order to explore their potential relationship. Eight high O(3) episode days were identified at WQS and two at TC during the sampling campaign, indicating a more serious O(3) pollution in Guangzhou than in Hong Kong. An observation-based model was employed to determine the ozone-precursor relationship. At both sites, O(3) production was found to be volatile organic compound (VOC)-limited, which is consistent with previous observations. Anthropogenic hydrocarbons played a key role in O(3) production, while reducing nitric oxide emissions aided the buildup of O(3) concentrations. Among VOC species, the summed relative incremental reactivity (RIR) of the top 12 compounds accounted for 89% and 85% of the total RIR at WQS and TC, respectively, indicating that local photochemical O(3) formation can be mainly attributed to a small number of VOC species.

DISCUSSION AND CONCLUSIONS

A large increment in both simulated HO(2) and O(3) concentrations was achieved with additional input of hourly carbonyl data. This suggested that apart from hydrocarbons, carbonyls might significantly contribute to the O(3) production in the Pearl River Delta.