P-wave terminal force in lead V1 and outcomes in patients with persistent atrial fibrillation undergoing catheter ablation.

AIMS: The P-wave terminal force in electrocardiogram lead V1 (PTFV1) correlates with outcomes in patients with paroxysmal atrial fibrillation (AF). Nevertheless, the correlation between the PTFV1 and outcomes after AF ablation in patients with persistent AF remains unclear. This study aimed to determine whether the PTFV1 at 3 months after AF ablation could predict AF recurrence and cardiovascular events in patients with persistent AF. METHODS: This historical cohort study examined 453 consecutive patients with persistent AF who underwent a first-time AF ablation. We measured the PTFV1 at 3 months after the ablation. An abnormal PTF was defined as a ≥4 mVms depression. The 3-year incidence of AF recurrence and composite cardiovascular events, including strokes, heart failure hospitalizations, and cardiovascular death, were compared between the abnormal and normal PTF groups. RESULTS: Among 434 enrolled patients, 101 had an abnormal, and 333 normal PTF at 3 months after AF ablation. Compared with the normal PTF group, the abnormal PTF group had a significantly higher incidence of AF recurrence (52.6% vs 28.1%, log-rank P < .001) and cardiovascular events (13.7% vs 2.6%, log-rank P = .005). After adjusting for the risk factors, an abnormal PTF was established as an independent predictor of AF recurrence (hazard ratio [HR] 2.12, 95% confidence interval [CI]: 1.44-3.13, P < .001) and cardiovascular events (HR 3.26, 95% CI: 1.19-8.97, P = .022). CONCLUSIONS: The PTFV1 at 3 months after AF ablation could be a valuable noninvasive predictor of both AF recurrence and cardiovascular events in patients with persistent AF.

Impact of direct oral anticoagulant use on mortality in very old patients with non-valvular atrial fibrillation.

BACKGROUND: the efficacy and safety of direct oral anticoagulants (DOACs) compared with that of warfarin in very old patients with non-valvular atrial fibrillation (NVAF) have been reported in terms of thromboembolisms and bleeding. However, the association of DOAC use and mortality in such patients remains unclear. OBJECTIVES: this study aimed to investigate the incidence of mortality, as well as thromboembolisms and major bleeding, in very old patients with NVAF using DOACs as compared with warfarin. METHODS: we conducted a single-centre historical cohort study of consecutive patients with NVAF aged ≥80 years who used oral anticoagulants. We compared the 5-year outcomes (all-cause mortality, thromboembolism, major bleeding and intracranial haemorrhage) between the DOAC and Warfarin groups. RESULTS: of 1,676 patients with atrial fibrillation aged 80 years and over, 1,208 with NVAF were included. Propensity score matching provided 461 patients in each group, and the risk of all-cause mortality, thromboembolisms, major bleeding and intracranial haemorrhages was significantly lower in the DOAC group than Warfarin group (hazard ratio [95% confidence interval] for DOAC use, 0.68 [0.54-0.87], 0.31 [0.19-0.53], 0.56 [0.36-0.88], 0.23 [0.10-0.56], log-rank P = 0.002, P < 0.001, P = 0.010, P < 0.001). The mortality rate within 1 year after major bleeding was significantly lower in the DOAC group than Warfarin group (14% versus 38%, P = 0.03), however, that after a thromboembolism was similar between the two groups (33% versus 35%). CONCLUSION: patients with NVAF aged ≥80 years and using DOACs had a lower mortality than those using warfarin.

Eicosapentaenoic Acid and the Outcomes in Older Patients Undergoing Atrial Fibrillation Ablation.

BACKGROUND: A lower serum eicosapentaenoic acid (EPA) to arachidonic acid (AA) ratio (EPA/AA) level correlates with cardiovascular events. Nevertheless, elevated serum EPA levels increase the risk of new-onset atrial fibrillation (AF) in older patients. The relationship between the EPA/AA and outcomes post-AF ablation remains unclear. This study investigated the impact of the EPA/AA on AF recurrence and cardiovascular events after AF ablation in older patients. METHODS AND RESULTS: This retrospective cohort study examined consecutive patients with AF aged ≥65 years who underwent a first-time AF ablation. We compared the 3-year AF recurrence and 5-year major adverse cardiovascular event (MACE) rates between patients divided into high and low EPA/AA levels defined as above and below the median EPA/AA value before ablation. MACE was defined as heart failure hospitalizations, strokes, coronary artery disease, major bleeding, and cardiovascular death. Among the 673 included patients, the median EPA/AA value was 0.35. Compared with the low EPA/AA group, the high EPA/AA group had a significantly higher cumulative incidence of AF recurrence (39.3% versus 27.6%; log-rank P=0.004) and lower cumulative incidence of MACE (13.8% versus 25.5%, log-rank P=0.021). A high EPA/AA level was determined as an independent predictor of AF recurrence (hazard ratio [HR], 1.75 95% CI, 1.24-2.49; P=0.002) and MACE (HR, 0.60 [95% CI, 0.36-0.99]; P=0.046). CONCLUSIONS: The EPA/AA was associated with AF recurrence and MACE after ablation in patients with AF aged ≥65 years.

Pre-procedural Stratification by the Endothelial Function in Patients with Heart Failure Undergoing Atrial Fibrillation Ablation.

BACKGROUND: Endothelial dysfunction (ED), a well-established risk marker of cardiovascular events, is associated with heart failure (HF) and atrial fibrillation (AF). Its relationship with cardiovascular events in patients with HF undergoing AF ablation remains unclear. We aimed to elucidate the association between ED and the outcomes after AF ablation in patients with HF. METHODS: This prospective cohort study included patients with HF who underwent an endothelial function assessment using the peripheral vascular reactive hyperemia index (RHI) before first-time AF ablation. We defined AF recurrence according to the following types: the conventional form (AF≥30 seconds) and persistent form (requiring cardioversion). An RHI<2.1 indicated ED. Those with and without ED were compared in terms of the 3-year incidence of AF recurrence and cardiovascular events after AF ablation. RESULTS: Among 421 patients with HF (69 ± 9 years and 38% females), 343 (81.5%) had ED. Although the incidence of the conventional form of AF recurrence was similar between the groups, that of the persistent form was significantly higher in the ED group (25.7% vs. 15.3%, log-rank P = 0.028). The ED group also had a significantly higher rate of cardiovascular events (14.8% vs. 3.6%, log-rank P = 0.028). Pre-procedural ED was identified as an independent predictor of a persistent form of AF recurrence (adjusted hazard ratio [HR] 2.31, 95% confidence interval [CI] 1.05-5.07, P = 0.037) and that of cardiovascular events (adjusted HR 4.21, 95% CI 1.02-17.5, P = 0.048), respectively. CONCLUSIONS: The endothelial function assessment enabled the risk stratification of clinically problematic outcomes after AF ablation in patients with HF.

Effect of Direct Slow Pathway Capture Mapping-Guided Ablation on Typical Atrioventricular Nodal Re-Entrant Tachycardia.

BACKGROUND: Direct slow pathway capture (DSPC) mapping is a novel electrophysiological technique for detecting antegrade slow pathway input sites. However, the effect of DSPC mapping-guided ablation on atrioventricular nodal re-entrant tachycardia (AVNRT) is unknown. OBJECTIVES: This study aimed to evaluate the efficacy and safety of DSPC mapping-guided ablation in typical AVNRT patients. METHODS: A multicenter retrospective study was conducted in 301 consecutive typical AVNRT patients. The outcomes in patients who underwent DSPC mapping-guided ablation (DSPC group) and those who underwent conventional anatomical ablation (conventional group) were compared. The conventional group was established before introducing DSPC mapping-guided ablation. Positive DSPC sites were defined as sites with a return cycle atrioventricular prolongation of ≥20 ms with high-output (10-20 V) pacing during tachycardia or the last paced beat of the atrial extrastimulation. RESULTS: Among 116 patients in the DSPC group, 102 (88%) had positive DSPC sites, and 86 (74%) had a successful ablation at that site. Of the remaining 30 patients, 27 had a successful anatomical ablation. The DSPC group had a significantly lower frequency of radiofrequency applications and shorter total application time than the conventional group (median: 5.5 [IQR: 3-11] times vs 9 [IQR: 5-15] times, and 168 [IQR: 108-266] seconds vs 244 [IQR: 158-391] seconds, respectively; P < 0.01). Moreover, the DSPC group had a numerically lower incidence of permanent pacemaker implantations and AVNRT recurrences than the conventional group (0% vs 1.6%; P = 0.17, and 1.7% vs 3.2%; P = 0.43, respectively). CONCLUSIONS: DSPC mapping-guided ablation was associated with a lower operative time, which can reduce the risk of AV conduction injury in typical AVNRT.

Serial changes in the trends of direct oral anticoagulant use and incidence of thromboembolisms and major bleeding events in very old patients with non-valvular atrial fibrillation.

Aims: Direct oral anticoagulants (DOACs) have become the first-line antithrombotic therapy in patients with non-valvular atrial fibrillation (NVAF). During this period, the incidence of thromboembolisms and major bleeding events has decreased. However, no studies have shown a correlation between them, and even fewer data are available on older patients. Therefore, we evaluated the serial changes in oral anticoagulant (OAC) use and the correlation between DOAC use and the incidence of adverse events among very old patients with NVAF. Methods and results: We conducted a historical cohort study in 1320 consecutive patients with NVAF aged ≥80 years who received medical treatment for AF from March 2011 to February 2021. We analysed the temporal trends regarding patients using OACs, including the DOAC prescription rate and incidence of adverse events. Over the last decade, the number of patients using OACs has increased from 228 to approximately 600 person-years. The DOAC prescription rate has significantly increased (4-90%, P < 0.001). The age of the patients and proportion of patients with a HASBLED score ≥3 significantly increased (84 ± 4 to 86 ± 4 years, 16-25%, P < 0.001, respectively). The composite incidence of thromboembolisms and major bleeding events significantly decreased (7.02-3.30 events/100 person-years, P < 0.001). Conclusion: The incidence of thromboembolisms and major bleeding events might be inversely correlated with the increase in the DOAC prescription rate in patients with NVAF aged ≥80 years.

Relationship Between Endothelial Dysfunction and the Outcomes After Atrial Fibrillation Ablation.

Background Endothelial dysfunction (ED) is associated with cardiovascular events in patients with atrial fibrillation (AF). However, the utility of ED as a prognostic marker after AF ablation supplementary to the CHA2DS2-VASc score is unclear. This study aimed to investigate the relationship between ED and 5-year cardiovascular events in patients undergoing AF ablation. Methods and Results We conducted a prospective cohort study of patients who underwent a first-time AF ablation and for whom the endothelial function was assessed by the peripheral vascular reactive hyperemia index (RHI) before ablation. We defined ED as an RHI of <2.1. Cardiovascular events included strokes, heart failure requiring hospitalization, arteriosclerotic disease requiring treatment, venous thromboses, and ventricular arrhythmias or sudden cardiac death. We compared the 5-year incidence of cardiovascular events after AF ablation between those with and without ED. Among the 1040 patients who were enrolled, 829 (79.7%) had ED, and the RHI value was found to be associated with the CHA2DS2-VASc score (P=0.004). The 5-year incidence of cardiovascular events was higher among patients with ED than those without ED (98 [11.8%] versus 13 [6.2%]; log-rank P=0.014). We found ED to be an independent predictor of cardiovascular events after AF ablation (hazard ratio [HR], 1.91 [95% CI, 1.04-3.50]; P=0.036) along with a CHA2DS2-VASc score of ≥2 (≥3 for women) (HR, 3.68 [95% CI, 1.89-7.15]; P<0.001). Conclusions The prevalence of ED among patients with AF was high. Assessing the endothelial function could enable the risk stratification of cardiovascular events after AF ablation.

Cardiovascular events and death after catheter ablation in very old patients with nonvalvular atrial fibrillation.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) is recommended for selected older patients. However, the preventive effects of AF ablation on cardiovascular events and death remain unclear, especially in older patients. This study aimed to investigate the impact of AF ablation on the incidence of cardiovascular events and death in very old nonvalvular AF (NVAF) patients. METHODS: We conducted a prospective cohort study of consecutive patients with NVAF aged ≥80 years and using direct oral anticoagulants (DOACs). We defined cardiovascular events as acute heart failure (AHF), strokes and systemic embolisms (SSEs), acute coronary syndrome (ACS), and sudden cardiac death (SCD) and cardiovascular death as AHF/SSE/ACS-related death and SCD. We compared the 3-year incidence of cardiovascular events and death between the patients who underwent AF ablation (Ablation group) and those who received medical therapy only (Medication group). RESULTS: Among the 782 NVAF patients using DOACs, propensity score matching provided 208 patients in each group. The Ablation group had a significantly lower 3-year incidence of cardiovascular events and death than the Medication group: cardiovascular events, 24 (13.2%) vs. 43 (23.3%), log-rank P = 0.009 and hazard ratio (HR) 0.52 (95% confidence interval (CI) 0.32-0.86) and cardiovascular deaths, 5 (3.0%) vs. 15 (7.8%), log-rank P = 0.019 and HR 0.32 (95% CI 0.16-0.88). CONCLUSIONS: In very old NVAF patients using DOACs, those who underwent AF ablation had a lower incidence of both cardiovascular events and death than those who received medical therapy only.

Prognostic Impact of the Early Use of Tolvaptan in Elderly Patients with Acute Decompensated Heart Failure.

The number of elderly patients with acute decompensated heart failure (ADHF) is increasing, and it is often difficult to treat. This study aimed to evaluate the efficacy and safety of using tolvaptan early after hospitalization in elderly patients with ADHF and the prognosis one year after hospitalization. This study enrolled 185 patients with ADHF who were admitted for the first time. Tolvaptan was administered within 24 h after admission. These patients were assigned to two groups: over 80 years old (n = 109) and under 80 years old (n = 76). There were no significant differences between the two groups in the occurrence of MACCE within one year (25% vs. 20%, p = 0.59). All-cause mortality was significantly higher in the over-80 group (12% vs. 2%, p = 0.01). There were no significant differences in the incidence of worsening renal failure (11% vs. 7%, p = 0.46) and hypernatremia (5% vs. 9%, p = 1.0), and in the duration of hospitalization (19.2 days vs. 18.8 days, p = 0.8). Tolvaptan might be effective and safe in elderly patients with ADHF, and there was no difference in the incidence of MACCE within one year.

Effect of Early Initiation of Evolocumab on Lipoprotein(a) in Patients with Acute Myocardial Infarction: Sub-Analysis of a Randomized Controlled Trial.

Elevated circulating lipoprotein(a) levels are associated with an increased risk of cardiovascular events. We reported that early initiation of evolocumab, a proprotein convertase subtilisin/kexin type 9 inhibitor, in addition to a statin substantially reduced the lipoprotein(a) levels in patients with acute myocardial infarction (AMI) after primary percutaneous coronary intervention (PCI). This sub-analysis sought to investigate the effect of evolocumab on lipoprotein(a) based on baseline lipoprotein(a) levels and characteristics. This study was a prespecified analysis of a randomized controlled trial that enrolled 102 patients who underwent primary PCI for AMI. Patients received pitavastatin (2 mg/day) alone or pitavastatin and evolocumab 140 mg subcutaneously within 24 h and 2 weeks after the index PCI. The evolocumab group showed significantly suppressed lipoprotein(a) levels in patients with baseline lipoprotein(a) levels of ≤10 mg/dL, 10 < lipoprotein(a) ≤ 20 mg/dL, and >20 mg/dL compared with the control group, as well as similar reductions in lipoprotein(a) levels in all patient subgroups. Among these subgroups, evolocumab tended to show more favorable effects in patients with diabetes mellitus. In AMI patients, early initiation of evolocumab therapy within 24 h of primary PCI suppressed the increase in lipoprotein(a) levels within 4 weeks, regardless of baseline levels and characteristics.

Secular Decreasing Trend in Plasma Eicosapentaenoic and Docosahexaenoic Acids among Patients with Acute Coronary Syndrome from 2011 to 2019: A Single Center Descriptive Study.

Despite intensive lipid-lowering interventions, patients treated with statins develop atherosclerotic cardiovascular disease (ASCVD), and these patients have an increased risk of developing recurrent cardiovascular events during follow-up. Therefore, there is a need to focus on the residual risks in patients in statin therapy to further reduce ASCVD. The aim of this study was to retrospectively investigate the 10-year trend (2011-2019) regarding changes in polyunsaturated fatty acids (PUFAs) in patients with acute coronary syndrome (ACS) in a single center. We included 686 men and 203 women with ACS admitted to Kagawa Prefectural Central Hospital. Plasma PUFAs, including eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), arachidonic acid (AA), and dihomo-γ-linolenic acid (DGLA), were measured at admission for suspected ACS. A secular decreasing trend in the levels of EPA and DHA and the EPA/AA ratio, but not of AA and DGLA, was observed. The analyses based on age (>70 or <70 years) and sex showed that the decreasing trend in the levels of EPA and DHA did not depend on age and remained significant only in men. Further studies are needed to obtain robust evidence to justify that the administration of n-3 PUFA contributes to the secondary prevention of ACS.

Effect of preprocedural pharmacologic cardioversion on pulmonary vein isolation in patients with persistent atrial fibrillation.

BACKGROUND: The optimal strategy for catheter ablation of persistent atrial fibrillation (PeAF) remains unknown. A preprocedural additive treatment for patients undergoing pulmonary vein isolation (PVI) alone to optimize catheter ablation should be investigated. OBJECTIVE: The purpose of this study was to determine whether pharmacologic cardioversion with a fixed low-dose antiarrhythmic drug (AAD) before ablation could stratify the long-term outcome of a PVI-alone strategy. METHODS: We conducted a prospective cohort study of PeAF patients who underwent PVI using contact force-sensing catheters. No substrate modification was performed. Fixed low-dose bepridil was administered before ablation for cardioversion and patients were classified into 2 groups based on obtaining sinus rhythm (SR). The rate of recurrence of atrial fibrillation (AF) and/or atrial tachycardia (AT) within 36 months was compared between the 2 groups. RESULTS: Among the 303 PeAF patients who received the AAD, 102 returned to SR (SR group), and the other 201 had persistence of AF (non-SR group). AF persistence duration at baseline and during bepridil administration was similar between the 2 groups. The SR group had a significantly lower 36-month AF/AT recurrence rate than the non-SR group (17 [22.2%] vs 55 [34.0%], log-rank P = .022). AT-type recurrence was observed in 16 patients (2 [3.3%] in the SR group vs 14 [8.9%] in the non-SR group; log-rank P = .051). Nonresponse to AAD was an independent predictor of AF/AT recurrence after adjusting for other risk factors (hazard ratio 1.34; 95% confidence interval 1.01-1.77; P = .040). CONCLUSION: Preprocedural pharmacologic cardioversion could be a useful determinant for patients with treatable PeAF by PVI alone.

Improvement in renal and endothelial function after catheter ablation in patients with persistent atrial fibrillation.

BACKGROUND: Cardiovascular events in patients with atrial fibrillation (AF) can be lowered by catheter ablation. We hypothesized the underlying mechanism was improvement in renal and endothelial function corresponding to AF burden, and investigated whether restoration of sinus rhythm (SR) after ablation affected these functions according to AF type. METHODS AND RESULTS: We prospectively measured estimated glomerular filtration rate (eGFR), urinary albumin-to-creatinine ratio (UACR), and reactive hyperemia index (RHI) in 358 consecutive patients with AF before and 6 and 12 months after the ablation. For each AF type [paroxysmal AF (PAF), n = 229, and persistent AF (PeAF), n = 129], we evaluated changes in these markers and influence of chronic kidney disease (CKD). The eGFR and natural logarithm-transformed (ln) UACR improved at 6 months in the PeAF group (68.7 ± 18.7-71.8 ± 18.9 mL/min/1.73 m2, p = 0.003 and 3.1±1.6 to 2.8±1.5, p < 0.001, respectively) and remained unchanged in the PAF group. Among the PeAF patients, recurrent AF was identified in 41, but only transiently in 38 patients. PeAF at baseline independently predicted increased eGFR [odds ratio (OR)=2.13, 95 % confidence interval (CI) 1.35-3.40, p = 0.001] and decreased UACR (OR=1.94, 95 % CI 1.05-3.58, p = 0.033). In the PeAF patients with CKD, ln-RHI significantly increased at 6 months after the ablation, and the change (Δ) in ln-RHI was significantly correlated with the ΔeGFR (r=0.35, p = 0.03). CONCLUSIONS: SR restoration after ablation was associated with an improved eGFR and UACR in PeAF patients, but not PAF patients. In PeAF patients with CKD, an improved endothelial function after ablation was associated with an improved renal function.

Differences in endothelial dysfunction induced by paroxysmal and persistent atrial fibrillation: Insights from restoration of sinus rhythm by catheter ablation.

BACKGROUND: Atrial fibrillation (AF) is associated with endothelial dysfunction. Studies have shown the incidence of cardiovascular events to be greater in patients with persistent AF (PeAF) than paroxysmal AF (PAF). OBJECTIVE: The aim of this study was to investigate whether endothelial dysfunction and the impact of catheter ablation on the endothelial function differs between PAF and PeAF. METHODS: We prospectively measured the endothelial function by reactive hyperemia peripheral arterial tonometry (RH-PAT) in 103 PAF, 75 PeAF, and 51 control patients at baseline, with follow-up in the AF patients at 6 and 12months after the catheter ablation. RESULTS: The log-transformed RH-PAT index (ln RHI) was the highest in the control group, followed by the PAF and PeAF (0.67±0.23, 0.57±0.29, and 0.45±0.3, respectively, p<0.001) groups. PeAF was determined to be an independent factor of endothelial dysfunction (ln RHI <0.55) even after adjustment for the conventional cardiovascular risk factors. For 12months after the catheter ablation, 102 (99%) PAF and 72 (96%) PeAF patients maintained sinus rhythm. On average, the ln RHI in the PAF group did not change during the follow-up, but it significantly increased in the PeAF group to a level comparable to that of the PAF patients 6months after the catheter ablation (0.53±0.28, p=0.034), and maintained the same level at 12months after the catheter ablation. CONCLUSIONS: The persistent form of AF may independently contribute to endothelial dysfunction. In addition, by catheter ablation, the maintenance of sinus rhythm may protect against exacerbations of endothelial dysfunction.

Early initiation of eicosapentaenoic acid and statin treatment is associated with better clinical outcomes than statin alone in patients with acute coronary syndromes: 1-year outcomes of a randomized controlled study.

BACKGROUND: Early initiation of EPA treatment in combination with a statin within 24h after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (MI) reduces inflammation and ventricular arrhythmia compared with statin monotherapy; however, the impact of early initiation of EPA treatment on cardiovascular events is unclear. We determined whether early eicosapentaenoic acid (EPA) treatment in patients with acute coronary syndrome (ACS) reduces adverse cardiovascular events. METHODS: This prospective, open-label, blind end point-randomized trial consisted of 241 patients with ACS. Patients were randomly assigned to receive pitavastatin (2mg/day) with or without 1800mg/day of EPA initiated within 24h after PCI. The primary endpoint was defined as cardiovascular events occurring within 1year, including death from a cardiovascular cause, nonfatal stroke, nonfatal MI and revascularization. RESULTS: The mean EPA/arachidonic acid ratio at follow-up was 0.40 in the control group and 1.15 in the EPA group. A primary endpoint event occurred in 11 patients (9.2%) in the EPA group and 24 patients (20.2%) in the control group (absolute risk reduction, 11.0%; hazard ratio, 0.42; 95% confidence interval, 0.21 to 0.87; P=0.02). Notably, death from a cardiovascular cause at 1year was significantly lower in the EPA group than in the control group (0.8% vs. 4.2%, P=0.04). CONCLUSIONS: Early initiation of treatment with EPA combined with statin after successful primary PCI reduced cardiovascular events after ACS. CLINICAL TRIAL REGISTRATION: UMIN Clinical Trials Registry (UMIN-CTR); Registry Number, UMIN000016723; URL, http://www.umin.ac.jp/ctr/index-j.htm.

Presence and characterization of prostaglandin D2-related molecules in nasal mucosa of patients with allergic rhinitis.

BACKGROUND: Prostaglandin D2 (PGD2) is the major prostanoid produced in the acute phase of allergic reactions. However, its pathophysiological role in addition to the pathway of production in allergic rhinitis remains unclear. We sought to determine the expression of synthases and receptors for PGD2 in human nasal mucosa. These expressions were compared between allergic and nonallergic patients. METHODS: The expression and localization of hematopoietic-type (h)-PGD2 synthase (PGDS) and lipocalin-type (l)-PGDS were detected by immunohistochemistry. The expression of D prostanoid (DP) receptor and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) was determined by quantitative real-time PCR. RESULTS: The h-PGDS but not l-PGDS was clearly expressed in nasal mucosa. The expression of h-PGDS in allergic patients was significantly higher than in control patients without mucosal hypertrophy. A variety of infiltrating cells including mast cells, eosinophils, macrophages, and lymphocytes as well as constitutive cells such as epithelial cells and fibroblasts expressed h-PGDS. The expression of both DP and CRTH2 was confirmed also. Although either the amount of DP or the amount of CRTH2 was not correlated with serum levels of IgE, the amount of CRTH2 but not DP was highly and significantly correlated with the number of eosinophils infiltrating into nasal musosa. CONCLUSION: These results suggest that PGD2 is released via the action of h-PGDS from various cells, and the expression of h-PGDS may be associated with the hypertrophic inflammation in the nose. In addition, ligation of PGD2 to CRTH2 appears to be selectively involved in eosinophil recruitment into the nose regardless of atopic status.