Polypill Strategy in Secondary Cardiovascular Prevention.

BACKGROUND: A polypill that includes key medications associated with improved outcomes (aspirin, angiotensin-converting-enzyme [ACE] inhibitor, and statin) has been proposed as a simple approach to the secondary prevention of cardiovascular death and complications after myocardial infarction. METHODS: In this phase 3, randomized, controlled clinical trial, we assigned patients with myocardial infarction within the previous 6 months to a polypill-based strategy or usual care. The polypill treatment consisted of aspirin (100 mg), ramipril (2.5, 5, or 10 mg), and atorvastatin (20 or 40 mg). The primary composite outcome was cardiovascular death, nonfatal type 1 myocardial infarction, nonfatal ischemic stroke, or urgent revascularization. The key secondary end point was a composite of cardiovascular death, nonfatal type 1 myocardial infarction, or nonfatal ischemic stroke. RESULTS: A total of 2499 patients underwent randomization and were followed for a median of 36 months. A primary-outcome event occurred in 118 of 1237 patients (9.5%) in the polypill group and in 156 of 1229 (12.7%) in the usual-care group (hazard ratio, 0.76; 95% confidence interval [CI], 0.60 to 0.96; P = 0.02). A key secondary-outcome event occurred in 101 patients (8.2%) in the polypill group and in 144 (11.7%) in the usual-care group (hazard ratio, 0.70; 95% CI, 0.54 to 0.90; P = 0.005). The results were consistent across prespecified subgroups. Medication adherence as reported by the patients was higher in the polypill group than in the usual-care group. Adverse events were similar between groups. CONCLUSIONS: Treatment with a polypill containing aspirin, ramipril, and atorvastatin within 6 months after myocardial infarction resulted in a significantly lower risk of major adverse cardiovascular events than usual care. (Funded by the European Union Horizon 2020; SECURE ClinicalTrials.gov number, NCT02596126; EudraCT number, 2015-002868-17.).

First time ACS in patients with on-target lipid levels: Inflammation at admission and re-event rate at follow-up.

BACKGROUND: Dyslipidaemia, inflammation and elevated Lp(a) levels are associated with the progression of atherosclerosis. This study investigates whether patients with a first-time presentation of chest pain and on-target LDL-C levels and intermediate FRS/ESC-Score risks, display a high inflammatory burden linked to myocardial injury and whether inflammation at admission affects the re-event rate up to 6 years follow-up. METHODS: Blind assessments of novel inflammatory markers such as Glycoprotein A and B via nuclear magnetic resonance (NMR), cytokines, hsCRP, Neutrophil-to-Lymphocyte ratio (NLR) and Lipoprotein(a) levels were examined. Out of 198 chest pain patients screened, 97 met the inclusion criteria at admission. RESULTS: cTnI(+) patients (>61 ng/L) with elevated Lipoprotein(a), showed significantly increased levels of Glycoprotein A and B, hsCRP, IL-6, a high NLR and a reduced left ventricular ejection fraction (%) compared to cTnI(-) individuals. Those patients, with a higher inflammatory burden at hospital admission (hsCRP, IL-6, Glycoprotein A and B, and Lipoprotein(a)) had a higher re-event rate at follow-up. CONCLUSIONS: Inflammation and Lipoprotein(a) levels were particularly prominent in patients presenting with reduced left ventricular ejection fraction. Notably, Glycoproteins A/B emerge as novel markers of inflammation in these patients. Our study highlights the significantly higher impact of inflammatory burden in patients with chest pain and high level of myocardial damage than in those with lower myocardial affectation, even when they all had lipid levels well controlled. Inflammation at the time of admission influenced the re-event rate over a follow-up period of up to 6 years.

Effect of dapagliflozin on COVID-19 infection and risk of hospitalization.

BACKGROUND: Dapagliflozin has been proposed as a potential treatment for coronavirus disease 2019 (COVID-19) by reducing cytokine production and inflammation. However, there are limited data on its effectiveness. We aimed to evaluate the impact of dapagliflozin on COVID-19 severity (including hospitalization risk, ICU admission, in-hospital death and progression to severe COVID-19) and its potential on susceptibility to COVID-19 infection. METHODS: We conducted a population-based case-control study. For aim 1, we assessed COVID-19 severity in cases (positive PCR patients requiring hospitalization) and matched controls (negative PCR patients or positive PCR patients not requiring hospitalization). For aim 2, we compared positive PCR cases (hospitalized and non-hospitalized) with controls. Adjusted odds ratios (aORs) were calculated using a generalized linear mixed model. RESULTS: We analysed 86 602 subjects: 3060 were hospitalized cases, 26 757 were non-hospitalized cases and 56 785 were controls. Among the hospitalized COVID-19 patients, 228 were admitted to the ICU and 413 died. Dapagliflozin had no effect on the risk of hospitalization (aOR 0.98; 95% CI 0.65-1.48; P = 0.915), ICU admissions (aOR 1.21; 95% CI 0.34-4.25; P = 0.767) or in-hospital death (aOR 1.33; 95% CI 0.53-3.30; P = 0.543). Dapagliflozin reduced the risk of progression to severe COVID-19 by 35%, but this was not statistically significant (aOR 0.65; 95% CI 0.40-1.06; P = 0.086). Dapagliflozin was associated with a 30% increased risk of susceptibility to COVID-19 infection (aOR 1.31; 95% CI 1.05-1.62; P = 0.015). CONCLUSIONS: Use of dapagliflozin prior to SARS-CoV-2 infection was not associated with an increased risk of hospitalization, ICU admission, mortality or progression to severe COVID-19. However, it was associated with an increased risk of susceptibility to COVID-19 infection.

Patients With High Cardiovascular Risk as Candidates to Bempedoic Acid, After Treatment With Statins, Ezetimibe and PCSK9 Inhibitors: An Estimation and Cost-Effectiveness Analysis.

ABSTRACT: Low-density lipoprotein cholesterol (LDLc) is the lead effector of atherosclerosis and main treatment target. Bempedoic acid is a novel oral drug in the therapeutic armamentarium which is able to reduce LDLc. The objectives of this study were (1) to select the potential patients for administering bempedoic acid such as those with a very high cardiovascular risk in which objectives of LDLc were not achieved despite conventional treatment with PCSK9 inhibitors (PCSK9i) and/or statins and ezetimibe and (2) to estimate the cost-effectiveness of bempedoic acid in different scenarios. The methods used were a multicenter and retrospective study of 652 patients initiating treatment with any PCSK9 inhibitor in 17 different hospitals. Before and on-treatment LDLc cholesterol levels, medical treatments, clinical indication, and baseline characteristics were recorded. The results obtained from 443 subjects in secondary prevention were analyzed. The mean (±) LDLc level at baseline was 142.5 ± 46.4 mg/dL and 61.5 ± 40.5 mg/dL in the follow-up, with a reduction of 55.9% ( P < 0.0001); 71.6% of the patients reached the target of LDL < 55 mg/dL or >50% reduction. Of those patients treated with medium-intensity and low-intensity statins plus PCSK9 inhibitors (with or without ezetimibe), only 5.7% of them were able to reduce LDL below 55 mg/dL and the main LDLc reduction in this group was the lowest (42.9% on average). Patients with TG values >135 mg/dL represented 41.6% of the sample, of which approximately 10% of them were using fibrates. Assuming only LDLc reduction and the UK price, the incremental cost-effectiveness ratio was 88,359€; 83,117€; 82,378€; and 79,015€ for different discount rates. In conclusion, one-third of the patients could achieve the target LDL proposed in the 2019 ESC/EAS guidelines. Approximately 10% of them could also benefit from treating hypertriglyceridemia as indicated in the 2021 ESC guidelines on cardiovascular disease prevention. Patients with medium-intensity and low-intensity statins plus PCSK9i and ezetimibe would be the most benefited. Bempedoic acid could be a not cost-efficacy therapy in all the scenarios, but we need to wait for the CLEAR OUTCOMES Trial results.

HDL Function and Size in Patients with On-Target LDL Plasma Levels and a First-Onset ACS.

Patients admitted for acute coronary syndrome (ACS) usually have high cardiovascular risk scores with low levels of high-density lipoprotein cholesterol (HDL-C) and high low-density lipoprotein cholesterol (LDL-C) levels. Here, we investigated the role of lipoprotein functionality as well as particle number and size in patients with a first-onset ACS with on-target LDL-C levels. Ninety-seven patients with chest pain and first-onset ACS with LDL-C levels of 100 ± 4 mg/dL and non-HDL-C levels of 128 ± 4.0 mg/dL were included in the study. Patients were categorized as ACS and non-ACS after all diagnostic tests were performed (electrocardiogram, echocardiogram, troponin levels and angiography) on admission. HDL-C and LDL-C functionality and particle number/size by nuclear magnetic resonance (NMR) were blindly investigated. A group of matched healthy volunteers (n = 31) was included as a reference for these novel laboratory variables. LDL susceptibility to oxidation was higher and HDL-antioxidant capacity lower in the ACS patients than in the non-ACS individuals. ACS patients had lower HDL-C and Apolipoprotein A-I levels than non-ACS patients despite the same prevalence of classical cardiovascular risk factors. Cholesterol efflux potential was impaired only in the ACS patients. ACS-STEMI (Acute Coronary Syndrome-ST-segment-elevation myocardial infarction) patients, had a larger HDL particle diameter than non-ACS individuals (8.4 ± 0.02 vs. 8.3 ± 0.02 and, ANOVA test, p = 0.004). In conclusion, patients admitted for chest pain with a first-onset ACS and on-target lipid levels had impaired lipoprotein functionality and NMR measured larger HDL particles. This study shows the relevance of HDL functionality rather than HDL-C concentration in ACS patients.

Effect of PCSK9 inhibitors on remnant cholesterol and lipid residual risk: The LIPID-REAL registry.

BACKGROUND: Monoclonal antibodies that inhibit the proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce low-density lipoprotein cholesterol (LDLc) by 55%, regardless of baseline treatments. Nonetheless, the effect of other lipid parameters, such as cholesterol remnants or, the so-called lipid residual risk, is unknown. METHODS: Multicenter and retrospective registry of patients treated with PCSK9 inhibitors from 14 different hospitals in Spain. Before and on-treatment lipid parameters were recorded. Residual lipid risk was estimated by (1) cholesterol remnants, (2) triglycerides/HDLc ratio (TG/HDL), (3) total cholesterol/HDLc (TC/HDL) and (4) the triglycerides-to-glucose index (TGGi). RESULTS: Six hundred fifty-two patients were analysed, mean age of 60.2 (9.63) years, 24.69% women and mean LDLc before treatment 149.24 (49.86) mg/dl. Median time to second blood determination was 187.5 days. On-treatment LDLc was 67.46 (45.78) mg/dl, which represented a 55% reduction. Significant reductions were observed for TG/HDL ratio, cholesterol remnants, TC/HDL ratio and TGGi. As consequence, 34.61% patients had LDLc <55 mg/dl and cholesterol remnants <30 mg/dl; additionally, 31.95% had cholesterol remnants <30 mg/dl but LDLc >55 mg/dl. Patients who had levels of cholesterol remnants >30 mg/dl before initiating the treatment with PCSK9 had higher reductions in cholesterol remnants, TG/HDL ratio, TC/HDL and TGGi. By contrast, no reduction differences were observed according to baseline LDLc (< or > the mean), age, gender or obesity. CONCLUSIONS: This multicenter and retrospective registry of real-world patients treated with PCSK9 inhibitors demonstrates a positive effect on cholesterol remnants and lipid residual risk beyond LDLc reductions.

Sex Differences in Low-Density Lipoprotein Cholesterol Reduction With PCSK9 Inhibitors in Real-world Patients: The LIPID-REAL Registry.

BACKGROUND: Previous evidence supports that monoclonal antibodies that inhibit the proprotein convertase subtilisin/kexin type 9 (PCSK9) reduce low-density lipoprotein cholesterol (LDLc) by 50%-65%, regardless of baseline treatments. We tested possible sex differences in a multicentre registry of real-world patients treated with PCSK9 inhibitors. METHODS: This is a multicentre and retrospective study of 652 patients initiating treatment with any PCSK9 inhibitor in 18 different hospitals. Before-treatment and on-treatment LDLc and medical treatments, clinical indication, and clinical features were recorded. RESULTS: Women represented 24.69% of the cohort. The use of statins was similar in both sexes, but women were receiving most frequently ezetimibe. Before-treatment median LDLc was 135 (interquartile range 115-166) mg, and it was higher in women. The median on-treatment LDLc was 57 (interquartile range 38-84) mg/dL, which represented a mean 54.5% reduction. On-treatment LDLc was higher in women, and the mean LDLc reduction was lower in women (47.4% vs. 56.9%; P = 0.0002) receiving evolocumab or alirocumab. The percentage of patients who achieved ≥50% LDLc reduction was higher in men (71.36% vs. 57.62%; P = 0.002). According to LDLc before-treatment quartiles, LDLc reduction was statistically lower in women in the 2 highest and a significant interaction of women and baseline LDLc >135 mg/dL was observed. Women were negatively associated with lower rates of LDLc treatment target achievement (odds ratio: 0.31). Differences were also observed in women with body mas index >25 kg/m2. Only 14 patients (2.14%) presented side effects. CONCLUSIONS: This multicentre and retrospective registry of real-world patients treated with PCSK9 inhibitors highlights significant gender differences in LDLc reduction.

Soluble ST2 and Diuretic Efficiency in Acute Heart Failure and Concomitant Renal Dysfunction.

BACKGROUND: Identifying patients at risk of poor diuretic response in acute heart failure (AHF) is critical to make prompt adjustments in therapy. The objective of this study was to investigate whether the circulating levels of soluble ST2 predict the cumulative diuretic efficiency (DE) at 24 and 72 hours in patients with AHF and concomitant renal dysfunction. METHODS AND RESULTS: This is a post hoc analysis of the IMPROVE-HF trial, in which we enrolled 160 patients with AHF and renal dysfunction (estimated glomerular filtrate rate of <60 mL/min/1.73 m2). DE was calculated as the net fluid output produced per 40 mg of furosemide equivalents. The association between sST2 and DE was evaluated by using multivariate linear regression analysis. The median cumulative DE at 24 and 72 hour was 747 mL (interquartile range 490-1167 mL) and 1844 mL (interquartile range 1142-2625 mL), respectively. The median sST2 and mean estimated glomerular filtrate rate were 72 ng/mL (interquartile range 47-117 ng/mL), and 34.0 ± 8.5 mL/min/1.73 m2, respectively. In a multivariable setting, higher sST2 were significant and nonlinearly related to lower DE both at 24 and 72 hours (P = .002 and P = .019, respectively). CONCLUSIONS: In patients with AHF and renal dysfunction at presentation, circulating levels of sST2 were independently and negatively associated with a poor diuretic response, both at 24 and 72 hours.

Long term prognostic benefit of complete revascularization in elderly presenting with NSTEMI: real world evidence.

The benefit of complete revascularization in elderly patients with non-ST elevation myocardial infarction (NSTEMI), and multivessel disease remains debated (MVD). The aim of our study was to determine the current long-term prognostic benefit of complete revascularization in this population. A retrospective cohort study of 1722 consecutive elderly NSTEMI patients was performed. Among the study participants 30.4% (n = 524) were completed revascularizated and in 69.6% (n = 1198) culprit vessel only revascularization was performed. A propensity score analysis was performed and we divided the study population into two groups: complete revascularization (n = 500) and culprit vessel only revascularization (n = 500). The median follow-up was 45.7 months, the all cause mortality (44.5% vs 30.5%, p < 0.001) (HR 0.74 (0.57-0.97); p = 0.035) and cardiovascular mortality (32.6% vs 17.4%, p < 0.001) (HR = 0.67 (0.47-0.94); p = 0.021) were significantly lower in patients with complete revascularization. In our study, we observed a long-term benefit of complete revascularization in elderly NSTEMI and MVD patients. Elderly patients should also be managed according to current guidelines to improve their long-term prognosis.

Multicenter and all-comers validation of a score to select patients for manual thrombectomy, the DDTA score.

BACKGROUND: Routine manual thrombectomy (MT) is not recommended in primary percutaneous coronary intervention (P-PCI) but it is performed in many procedures. The objective of our study was validating the DDTA score, designed for selecting patients who benefit most from MT. METHODS: Observational and multicenter study of all consecutive patients undergoing P-PCI in five institutions. Results were compared with the design cohort and the performance of the DDTA was analyzed in all patients. Primary end-point of the analyses was TIMI 3 after MT; secondary endpoints were final TIMI 3, no-reflow incidence, in-hospital mortality and in-hospital major cardiovascular events (MACE). In-hospital prognosis was assessed by the Zwolle risk score. RESULTS: Three hundred forty patients were included in the validation cohort and no differences were observed as compared to the design cohort (618 patients) except for lower use of MT and higher IIb/IIIa inhibitors or drug-eluting stents. The probability of TIMI 3 after MT decreased as delay to P-PCI was higher. If DDTA score, MT was associated to TIMI 3 after MT (OR: 4.11) and final TIMI 3 (OR: 2.44). There was a linear and continuous relationship between DDTA score and all endpoints. DDTA score ≥ 4 was independently associated to lower no-reflow, in-hospital MACE or mortality. The lowest incidence of in-hospital mortality or MACE was in patients who had DDTA score ≥ 4 and Zwolle risk score 0-3. CONCLUSIONS: MT is associated to higher rate of final TIMI3 in patients with the DDTA score ≥ 4. Patients with DDTA score ≥ 4 had lower no-reflow and in-hospital complications.

Direct Oral Anticoagulants Versus Vitamin-K Antagonist After PCIs in Patients With AF: A Meta-analysis of Cardiac Ischemic Events.

BACKGROUND: Clinical trials have assessed the effect of direct oral antagonists (DOACs) in patients with atrial fibrillation (AF) after percutaneous coronary interventions (PCI). Studies were designed to test the effect on bleeding incidence, but concerns related to safety on ischemic events remain. METHODS: We performed a meta-analysis with currently available studies involving DOACs versus Vitamin-K antagonist (VKA) in patients with AF after PCI. The primary endpoint was the incidence of cardiac ischemic events, including myocardial infarction and stent thrombosis. Secondary endpoints were the incidence of stroke, all-cause mortality, and major bleeding. RESULTS: Eleven thousand twenty-three patients were included in the analysis: 5510 receiving DOACs and 5513 VKA. A total of 190 cases of myocardial infarction were registered in patients treated with DOACs and 177 in patients on VKA, and no statistical difference was noted [relative risk (RR): 1.07 95% confidence interval (CI) 0.88-1.31]. The incidence of stent thrombosis was very low with no differences between both treatment strategies (RR: 1.14 95% CI 0.76-1.71). The incidence of cardiac ischemic events was the same in patients receiving DOACs or VKA (HR 1.09 95% CI 0.91-1.30). No differences were observed in the incidence of stroke (RR: 0.86 95% CI 0.61-1.23) or mortality (RR: 1.09, 95% CI 0.90-1.31). Treatment with DOACs was associated with 34% reduction in major bleeding (RR: 0.66, 95% CI 0.54-0.81). CONCLUSIONS: Treatment with DOACs in patients with AF after a PCI do not increase the risk of cardiac ischemic events, stroke, or death and reduce the incidence of major bleeding by 34% as compared with VKA.

Diabetes mellitus, frailty and prognosis in very elderly patients with acute coronary syndromes.

BACKGROUND: The magnitude of the association between diabetes (DM) and outcomes in elderly patients with acute coronary syndromes (ACS) is controversial. No study assessed the prognostic impact of DM according to frailty status in these patients. METHODS: The LONGEVO-SCA registry included unselected ACS patients aged ≥ 80 years. Frailty was assessed by the FRAIL scale. We evaluated the impact of previous known DM on the incidence of death or readmission at 6 months according to status frailty by the Cox regression method. RESULTS: A total of 532 patients were included. Mean age was 84.3 years, and 212 patients (39.8%) had previous DM diagnosis. Patients with DM had more comorbidities and higher prevalence of frailty (33% vs 21.9%, p = 0.002). The incidence of death or readmission at 6 months was higher in patients with DM (HR 1.52, 95% CI 1.12-2.05, p 0.007), but after adjusting for potential confounders this association was not significant. The association between DM and outcomes was not significant in robust patients, but it was especially significant in patients with frailty [HR 1.72 (1.05-2.81), p = 0.030, p value for interaction = 0.049]. CONCLUSIONS: About 40% of elderly patients with ACS had previous known DM diagnosis. The association between DM and outcomes was different according to frailty status.

Impact of dynamic physical exercise on high-risk definite arrhythmogenic right ventricular cardiomyopathy.

INTRODUCTION: Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is an inherited cardiomyopathy characterized by ventricular arrhythmias and heart failure. The variable phenotype suggesting that determined environmental factors may have an influence. The aim of our study was to discover the impact of the dynamic physical activity on patients with high-risk definite ARVC/D. METHODS AND RESULTS: Collection of data on physical activity at the time of diagnosis was conducted at an in-person clinical interview. The intensity of the activity was classified in accordance with the mean frequency of weekly physical exercise sessions in the 10 years before diagnosis and into the following three groups of dynamic activity: high/competitive (>3 h/wk), moderate (1 to 3 h) and minimal/inactive (<1 h). Seventeen patients practiced high dynamic physical activities. The intensity of dynamic activity was classified into three groups: 8 of high intensity, 9 moderate, and 19 inactive. The first major arrhythmic event and occurrence of severe right ventricular dysfunction were earlier in the high-intensity exercise group, followed by the moderate intensity group and at a later age in the low-intensity/inactive group. CONCLUSIONS: Dynamic exercise could be directly associated with the severity of the phenotype in relation to the precocity of major ventricular arrhythmic events and right ventricular systolic dysfunction in patients with high-risk definite ARVC/D.

Relevance of Dementia in Atrial Fibrillation Patients within a Specific European Health Care Area.

INTRODUCTION: Atrial fibrillation might increase the risk of dementia. We aim to test the hypothesis that dementia could reclassify the actual risk of stroke and death predicted by the CHA2DS2-VASc in patients with atrial fibrillation (AF). METHODS: A prospective study performed in a specific health care area. RESULTS: From our health care area (n = 348,985), throughout 2013, AF was codified in 7,990 (2.08%). Mean age was 76.83 ± 10.5, mean CHA2DS2-VASc = 3.5, 4,056 (50.8%) were females and 287 (3.6%) were diagnosed to have dementia. Patients with dementia were older and presented a higher rate of all the components of the CHA2DS2-VASc-expect vasculopathy. Differences in overall mortality were observed but not in stroke and haemorrhagic events. After propensity score matched analysis, dementia was independently associated with all-cause mortality. Addition of dementia to CHA2DS2-VASc reclassified 7.7 and 16.6% of the cohort with regard to thromboembolic events and death risk respectively. CONCLUSIONS: Patients with dementia presented a more adverse risk profile, with significant differences in all-cause mortality.

Nutrients restriction upregulates adiponectin in epicardial or subcutaneous adipose tissue: impact in de novo heart failure patients.

Background: Hyperadiponectinemia is an indicator of worse outcomes in advanced heart failure (HF), its role in de novo HF is less clear. Objective: Because this protein is a hormone with starvation properties, we wanted to know its association with nutritional state and its regulator factors in de novo HF. Methods: Adiponectin circulating levels were determined by ELISA at discharge in patients admitted for de novo HF (n=74). Nutritional status was determined by CONUT score. Univariate and multivariate Cox regression analyses were employed to calculate the estimated hazard ratio (HR) with 95% confidence interval (CI) for death or all-cause readmission. Stromal vascular cells (SVC) of EAT and subcutaneous adipose tissue (SAT) from patients (n=5) underwent heart surgery were induced to adipogenesis for 18 days. Then, cells were cultured with complete or starved medium for 8 hours. At the end, adiponectin expression levels were analysed by real time polymerase chain reaction. Results: Patients were grouped regarding nutritional status. There was a strong association between high adiponectin levels and failing nutritional status. Those patients with worse nutritional state had the highest adiponectin and proBNP levels at discharge (p<0.01). Both proteins were slightly correlated (p<0.05). However, only high adiponectin levels were independently associated with death or all-cause readmission. Nutrients starvation upregulated adiponectin expression levels in adipogenesis-induced SVC from EAT or SAT. Conclusions: Worse nutritional state in de novo HF patients is associated with higher adiponectin plasma levels. Their levels were upregulated in adipose cells after being nutrients-starved. These results may help us to understand the adiponectin paradox in HF.

Doramectin in the treatment of generalized demodicosis.

BACKGROUND: Generalized demodicosis is a common disease in dogs and doramectin has been reported as a successful treatment. Different treatment protocols using doramectin have not been previously evaluated. OBJECTIVE: To evaluate whether oral administration of doramectin twice a week is more effective than administration by subcutaneous injection once a week. ANIMALS: Twenty nine privately owned dogs affected with generalized demodicosis. METHODS: Dogs randomly received one of two treatments. Sixteen dogs were treated with 600 µg/kg doramectin by subcutaneous injection once a week and 13 dogs received 600 µg/kg doramectin by oral administration twice a week. RESULTS: The mean age of affected dogs was 2.8 and 2.6 years (P = 0.587) and the mean mite number detected at the initial evaluation was 201 and 287 (P = 0.04), respectively, for each group. The mean time to achieve negative skin scrapings was 13 and 12 weeks, respectively (P = 0.955). Adult-onset demodicosis affected five of 16 and two of 13 dogs, respectively (P = 0.662). The success rate for treatment was 13 of 16 (81%) of dogs receiving subcutaneous injections once a week and 12 of 13 (92%) dogs receiving oral dosaging twice a week. (P = 0.691). Four dogs did not achieve disease remission. In the 12 month follow-up period, one dog that had received the once a week protocol relapsed after eight weeks of treatment withdrawal. Adverse effects were not observed in any dog. CONCLUSION: Based on the results of this study, oral administration of doramectin twice a week does not achieve a more rapid resolution of canine generalized demodicosis than administration by subcutaneous injection once a week. The treatment success rate was the same for both protocols.