Clinical characteristics and treatment patterns in patients with atherosclerotic cardiovascular disease with hypercholesterolemia: a retrospective analysis of a large US real-world database cohort.

OBJECTIVE: Guidelines developed by the American College of Cardiology/American Heart Association (ACC/AHA) recommend lipid-lowering therapies (LLTs) to reduce low-density lipoprotein cholesterol (LDL-C) and atherosclerotic cardiovascular disease (ASCVD) risk. This study described LLT utilization patterns and LDL-C goal achievement (to <70 mg/dL) among patients with ASCVD in the United States. METHODS: This retrospective study was conducted using Optum's de-identified Clinformatics Data Mart Database (CDM). Patients with their first ASCVD diagnosis (index date) in the CDM database between July 1, 2015, and December 31, 2018, were followed for ≥12 months to assess LLT utilization patterns and change in LDL-C. LLTs included were statins and non-statin LLTs (ezetimibe, fibrates, and proprotein convertase subtilisin/kexin type 9 inhibitors). Adherence was measured as the proportion of days covered (PDC), defined as the number of days with drug on-hand (or number of days exposed to drug) divided by the 12-month follow-up period. Patients with PDC ≥0.8 were considered adherent. RESULTS: Among the patients with ASCVD (N = 1,424,893) included in this study, only 621,978 (43.7%) had at least one LDL-C measurement at baseline (6 months prior to and 3 months after the index date). The mean age was 71.5 years, and almost half of the patients were female. Patients were followed for a mean (standard deviation [SD]) duration of 30.6 (11.4) months (median of 29.9 months). During the follow-up, about one-quarter of the patients did not receive any LLT. Among treated patients, 89.5% received statins and 10.5% received non-statin LLT. Less than half (47.6%) of the patients were adherent to the index treatment during the 12-month follow-up. Even in patients receiving combination therapy (statin + non-statin LLT), a sizable proportion (35.8%) showed an increase in LDL-C over the follow-up period. CONCLUSIONS: This retrospective study highlighted limited LDL-C monitoring in patients with ASCVD, and unmet need in terms of suboptimal utilization of non-stain LLTs, limited adherence to LLTs, and inadequate lipid control after treatment (among those with LDL-C measurements during the follow-up period) need to be addressed to improve outcomes in this patient cohort.

International societies of cardiologists recommend use of medications to lower the "bad" cholesterol, and its risk of cardiovascular diseases like stroke. We aimed to describe how those medications are being used and to what extent patients with cardiovascular diseases in the United States have their "bad" cholesterol under control. Results of this study indicate that cholesterol check-up among the patients was limited. Among recommended medications, statins were mostly used, whereas use of other recently approved medications was minimal. One-quarter of patients were not prescribed medications to control their cholesterol. Moreover, patients were not taking the medications as frequently as prescribed.

Nationwide trends in hospitalization, medical costs, and mortality for asthma after introduction of biologics: A cross-sectional study in the United States.

BACKGROUND: Asthma is the most common inflammatory lung disease in the United States. Since 2015, biologic therapies have provided targeted treatment for patients with severe asthma. OBJECTIVE: To evaluate the trends for in-hospital outcomes of asthma before (2012-2014) and after (2016-2018) the introduction of biologic therapies for asthma. METHODS: We conducted a nationwide cross-sectional analysis of patients aged 2 years or older who were hospitalized for asthma between 2012 and 2018 using data from the Nationwide Readmissions Database. Outcomes included rates of asthma hospital admission and asthma-related 30-day readmission, hospital length of stay, hospital costs, and inpatient mortality. Generalized linear models assessed trends in rates of asthma admission and readmission, length of stay, costs, and mortality quarterly during 2012-2014 and 2016-2018. RESULTS: Among 691,537 asthma-related admissions, quarterly asthma admission rates significantly decreased (-0.90%, 95% CI = -1.46% to - 0.34%; P = 0.002) during 2016-2018, mainly among adults, but not during 2012-2014. Quarterly assessed readmission rates decreased by 2.40% (-2.85% to -1.96%; P < 0.0001) during 2012-2014 and by 2.12% (-2.74% to - 1.50%; P < 0.0001) during 2016-2018. Mean length of stay for asthma admissions decreased quarterly by 0.44% (-0.49% to - 0.38%; P < 0.0001) during 2012-2014 and by 0.27% (-0.34% to - 0.20%; P < 0.0001) during 2016-2018. Quarterly hospital costs for admissions were unchanged during 2012-2014 but increased by 0.28% (0.21% to 0.35%; P < 0.0001) during 2016-2018. There were no significant trends in inpatient mortality during 2012-2014 and 2016-2018. CONCLUSIONS: After the introduction of new biologics for severe asthma in 2015, asthma-related hospital admissions decreased significantly, whereas hospital costs increased. Asthma-related 30-day readmission rates and length of stay for asthma admissions continuously decreased, whereas inpatient mortality rates remained stable. DISCLOSURES: This work was supported by the National Heart, Lung, And Blood Institute of the National Institutes of Health under Award Number R01HL136945. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The data that support the findings of this study are available from the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project but restrictions apply to the availability of these data, which were used under license for the current study, and so are not publicly available. Data are however available from the authors upon reasonable request and with permission of the Agency for Healthcare Research and Quality's Healthcare Cost and Utilization Project.

Characteristics and lipid lowering treatment patterns in patients tested for lipoprotein(a): A real-world US study.

Objective: Elevated lipoprotein(a) [Lp(a)] is a risk factor for atherosclerotic cardiovascular disease (ASCVD) and has no approved pharmacotherapies. Limited real-world data exists on the proportion of patients with available Lp(a) test results, characteristics of these patients, and their use of lipid lowering therapies (LLTs) for secondary prevention (SP) and primary prevention (PP) of ASCVD. Methods: Patients with measured Lp(a) receiving LLTs for SP or PP of ASCVD were identified in the Optum Clinformatics® Data Mart database. Lp(a) distribution and LLT utilization including persistence and adherence were assessed. Logistic regression was used to assess the association between Lp(a) levels and low-density lipoprotein cholesterol (LDL-C) levels after index LLT, adjusting for baseline characteristics. Results: Overall, 2154 SP and 7179 PP patients met eligibility criteria. Of patients with available laboratory data, only 0.7% (SP) and 0.6% (PP) had Lp(a) test results. In the SP cohort, Lp(a) levels ≥125 nmol/L and ≥175 nmol/L were 26.4% and 17.6%, respectively, and the mean (SD) Lp(a) levels (overall SP cohort 90.4 [97.9] nmol/L) were highest in Black patients (123.4 [117.4]; p<0.001). Statin monotherapy was the most frequently prescribed LLT in SP patients overall (89.4%). Median (interquartile range [IQR]) persistence of LLTs was 227 (91, 649) days and 33.6% achieved ≥80% proportion of days covered (PDC). Patients with Lp(a) ≥175 nmol/L had 2.1 times greater odds of having elevated LDL-C (≥70 mg/dL) post-LLT than those with Lp(a) <175 nmol/L (p = 0.031). Similar findings were observed in the PP population. Conclusions: Lp(a) screening was rare. Elevated Lp(a) was observed in more than one-quarter of patients receiving LLTs, with the highest mean Lp(a) levels observed in Black patients. Low adherence to LLTs was prevalent and at least half of patients failed to achieve their respective LDL-C target thresholds despite treatment. Finally, high Lp(a) levels were associated with worse LDL-C control.

Adherence to Adjuvant Endocrine Therapy and Survival Among Older Women with Early-Stage Hormone Receptor-Positive Breast Cancer.

BACKGROUND AND OBJECTIVE: Although improving adherence to adjuvant endocrine therapies (AETs) is critical to ensure better patient outcomes, the evidence is still lacking on differences in 5-year AET adherence trajectories. This study aimed to estimate the time trend of adherence by the type of individual AET and the association of adherence to AETs with overall survival among older women with hormone receptor-positive breast cancer. METHODS: This study used the Surveillance, Epidemiology, and End Results-Medicare database 2006-2016. We included women aged ≥ 65 years with newly diagnosed hormone receptor-positive breast cancer and who had initiated AET (anastrozole, letrozole, exemestane, or tamoxifen). Adherence to AETs was defined as the proportion of days covered that was calculated for the follow-up period (5 years). The overall survival time was defined as the time from the date of AET initiation to death. The linear mixed models with repeated measures were used to estimate the changes in adherence to AETs. The Cox proportional hazard model was used to assess the relationships (hazard ratio [HR] and 95% confidence interval [CI]) between adherence to AETs and death. RESULTS: A total of 11,617 patients were included. Anastrozole was the most commonly used (n = 6,908), followed by letrozole (n = 2,586), tamoxifen (n = 1,750), and exemestane (n = 373). The mean (standard deviation) of proportion of days covered for 5 years was 57.4 (34.6), indicating the highest proportion of days covered in the anastrozole group [61.1 (34.1)] and the lowest proportion of days covered in the exemestane group [44.0 (35.1)]. Overall, adherence to AET decreased over the 5-year follow-up period in all AET groups, but the decrease in the tamoxifen group was steeper (42.3% decreased) compared with other AETs. Anastrozole, letrozole, and exemestane groups were associated with a lower risk of death compared with the tamoxifen group (HR = 0.80, 95% CI 0.71-0.89 for anastrozole; HR = 0.82, 95% CI 0.72-0.93 for letrozole; HR = 0.82, 95% CI 0.63-1.07 for exemestane). CONCLUSIONS: Patients who initiated with tamoxifen had a steeper decrease in adherence over the 5 years compared with anastrozole, letrozole, and exemestane groups. Furthermore, higher adherence was associated with a decreased risk of mortality. Physicians should be cognizant of decreasing adherence over time and choose effective treatment options with minimal side-effect profiles to better support adherence by patients with breast cancer.

Antihypertensive Use and the Risk of Alzheimer's Disease and Related Dementias among Older Adults in the USA.

BACKGROUND: Epidemiological evidence on different classes of antihypertensives and risks of Alzheimer's disease and related dementias (ADRD) is inconclusive and limited. This study examined the association between antihypertensive use (including therapy type and antihypertensive class) and ADRD diagnoses among older adults with hypertension. METHODS: A retrospective, cross-sectional study was conducted, involving 539 individuals aged ≥ 65 years who used antihypertensives and had ADRD diagnosis selected from 2013 to 2018 Medical Expenditure Panel Survey (MEPS) data. The predictors were therapy type (monotherapy or polytherapy) and class of antihypertensives defined using Multum Lexicon therapeutic classification (with calcium channel blockers [CCBs] as the reference group). Weighted logistic regression was used to assess the relationships of therapy type and class of antihypertensives use with ADRD diagnosis, adjusting for sociodemographic characteristics and health status. RESULTS: We found no significant difference between monotherapy and polytherapy on the odds of ADRD diagnosis. As to monotherapy, those who used angiotensin-converting enzyme inhibitors (ACEIs) had significantly lower odds of developing AD compared to those who used CCBs (OR 0.36, 95 % CI 0.13-0.99). CONCLUSIONS: Findings of the study suggest the need for evidence-based drug therapy to manage hypertension in later adulthood and warrant further investigation into the mechanism underlying the protective effect of antihypertensives, particularly ACEIs, against the development of AD among older adults with hypertension.

A National Catalog of Mapped Short-Form Six-Dimension Utility Scores for Chronic Conditions in the United States From 2010 to 2015.

OBJECTIVES: This study examined health preference utility weights and utility decrements associated with different types of chronic conditions in the United States. METHODS: We used the 2010-2015 Medical Expenditure Panel Survey data for persons aged ≥ 18 years with 12-Item Short-Form Survey Physical and Mental Component Summary scores. 12-Item Short-Form Survey scores were converted to Short-Form Six-Dimension (SF-6D) preference scores to measure utilities of different chronic diseases. We used the Clinical Classification Code to identify 30 chronic diseases from 12 categories, such as cardiovascular diseases, cerebrovascular diseases, hypertension, hyperlipidemia, obesity, cancers, musculoskeletal diseases, endocrine or metabolic diseases, oral diseases, respiratory diseases, and mental disorders. A generalized linear model was used to quantify the utility decrements for 30 chronic diseases, controlling for demographic characteristics. RESULTS: We identified 132 737 adults (mean age 47.2 years, 52.2% female, 80% white); 73% had at least one identified chronic disease, and the mean SF-6D was 0.786. Among 30 chronic diseases, the unadjusted mean SF-6D scores of patients with cognitive disorder (0.607) were the lowest, followed by congestive heart failure (0.629), rheumatoid arthritis (0.654), and lung cancer (0.662). After controlling for demographic variables (ie, age, sex) and comorbidities, cognitive disorders (-0.116), mood disorders (-0.099), rheumatoid arthritis (-0.090), liver cancer (-0.078), and stroke (-0.063) showed the highest decrements in the SF-6D scores (P < .05). CONCLUSIONS: This study provides a nationally representative catalog of utility weights for major chronic diseases in the US general population. The utility decrements will enable researchers to calculate the health utilities of patients with multiple comorbid diseases.

Association of congestive heart failure with hospital outcomes among renal cancer patients in the United States: analysis of nationwide inpatient sample.

Background: Patients with renal cancer are at increased risk of comorbid congestive heart failure (CHF) due to several shared risk factors and the cardiotoxicity of some medications used for renal cancer treatment. We aimed to examine the relationship between CHF and hospital outcomes among renal cancer patients in the U.S.Methods: In this cross-sectional study, we identified hospitalizations of renal cancer patients using the 2015-2017 National Inpatient Sample. We assessed the relationship between CHF and hospital outcomes in this patient population, including in-hospital mortality, length-of-stay (LoS), and hospital costs.Results: Among the 20,321 hospitalizations of renal cancer patients identified, 6.1% involved patients with comorbid CHF (n = 1,231). The odds of in-hospital mortality did not differ based on CHF presence (odds ratio = 1.21; p = 0.354). Hospitalizations of renal cancer patients with CHF were associated with a greater LoS (incidence rate ratio = 1.44; p < 0.001) and higher hospital costs (cost ratio = 1.27; p < 0.001) than those without CHF.Conclusions: CHF in renal cancer patients is associated with increased LoS and higher hospital costs. These findings suggest that optimal management of comorbid CHF may improve hospital outcomes in patients with renal cancer and provides evidence to support the emerging field of cardio-oncology.

A network meta-analysis of efficacy and safety of first-line and second-line therapies for the management of metastatic renal cell carcinoma.

WHAT IS KNOWN AND OBJECTIVE: Metastatic renal cell carcinoma (mRCC) is the most common type of kidney cancers. Disease-specific survival for mRCC has been significantly improved with the introduction of new targeted agents since 2005. However, there is a lack of head-to-head clinical trials comparing the efficacy between therapies. This study compared indirectly progression-free survival (PFS) and overall survival (OS) among first-line and second-line therapies in patients with mRCC using network meta-analysis (NMA). METHODS: The PubMed, MEDLINE, Cochrane Library and Web of Science were searched to identify phase II or phase III randomized controlled trials (RCTs) of targeted and biological therapies in patients with mRCC published between January 2000 and June 2020. The Bayesian fixed-effect NMA was performed to evaluate relative PFS and OS of first-line and second-line therapies of axitinib, bevacizumab, cabozantinib, everolimus, lenvatinib, nivolumab, ipilimumab, pazopanib, sorafenib, sunitinib, temsirolimus, tivozanib, avelumab and pembrolizumab, which were approved by the Food and Drug Administration or European Medicines Agency. End points were compared using hazard ratio (HR) and 95% credible interval (CrI). The surface under the cumulative ranking curve (SUCRA) was estimated to assess the probability of being the best treatment. RESULTS AND DISCUSSION: A total of 26 RCTs (first line: 19, second line: 9) with 13 893 patients were included in the NMA. For the first-line therapy, cabozantinib was associated with the highest improved PFS (HR = 0.26, 95% CrI = 0.14-0.44) followed by avelumab + axitinib and pembrolizumab + axitinib (HR = 0.27, SUCRA = 90%). Pembrolizumab + axitinib had a high likelihood of being the preferred treatment when using OS as the outcome measure (HR = 0.41, 95% CrI = 0.16-0.85). Avelumab + axitinib had the lowest HR compared with placebo + interferon on discontinuations due to AE (HR = 1.04, 95% CrI = 0.54-1.86). For second-line therapy, cabozantinib was identified as the most effective treatment option when assessing PFS (HR = 0.17, 95% CrI = 0.12-0.24). Axitinib had the lowest HR of OS and discontinuation due to AE (HR = 0.54, 95% CrI = 0.40-0.71; HR = 0.98, 95% CrI = 0.42-1.97, respectively). Pazopanib was the second choice in terms of OS (HR = 0.56, 95% CrI = 0.28-1.00; SUCRA = 76%) compared with placebo. WHAT IS NEW AND CONCLUSION: With respect to PFS and OS improvement, cabozantinib, avelumab + axitinib and pembrolizumab + axitinib are likely to be the preferred options for the first-line therapy and cabozantinib and axitinib for the second-line therapy in the management of mRCC. Regarding safety, avelumab + axitinib and temsirolimus were considered preferred treatment options in first-line and second-line therapies. More future research is needed to establish subgroup analyses, allowing evaluation of the impact of some of the differences in patient characteristics, including treatment effect modifiers.

Comparison of Prostaglandin Analog Treatment Patterns in Glaucoma and Ocular Hypertension.

BACKGROUND: Prostaglandin analogs (PGAs) are considered an initial therapy to manage increased intraocular pressure (IOP) for patients with glaucoma. When the initial PGA treatment fails to lower IOP adequately, the patient may add or change medications or have surgery/laser treatment. OBJECTIVE: To compare medication adherence, duration of therapy, and treatment patterns among 3 PGAs-latanoprost, travoprost, and bimatoprost-as initial therapies for patients with glaucoma or ocular hypertension. METHODS: This was a retrospective cohort study using administrative claims data. The cohort consisted of patients newly diagnosed with glaucoma or ocular hypertension with at least 1 prescription claim for latanoprost, travoprost, or bimatoprost and enrolled in a Medicare Advantage plan between 2007 and 2012. The 24-month medication possession ratio (MPR) was used to measure medication adherence. Discontinuation of first-line PGA therapy was defined as nonpersistence (90-day gap allowance) of the index PGA or a change in therapy during the 24-month follow-up period. Types of second-line therapy (i.e., switch, addition, and surgery) were identified. The 1:1:1 propensity score matching was used. RESULTS: Patients who met the inclusion criteria were propensity score matched, resulting in 1,296 patients per PGA group. Latanoprost users showed higher adherence (50.1%) than travoprost (48.8%) and bimatoprost (43.0%) users. The latanoprost and travoprost groups had significantly higher MPRs than bimatoprost (P < 0.0001). The latanoprost group showed significantly longer duration of first-line therapy (372 days) than the bimatoprost group (343 days; P = 0.003) but not the travoprost group (361 days). After controlling for demographic and clinical characteristics, a Cox proportional hazards model showed that the travoprost and bimatoprost groups had a higher risk of discontinuation of first-line therapy than the latanoprost group (P < 0.0001). The percentage of patients continuing on the index PGA without treatment pattern change (i.e., switches, additions, and surgery) was higher for latanoprost users (52.9%) compared with travoprost (39.0%) or bimatoprost users (42.1%; P < 0.001). CONCLUSIONS: Patients who used latanoprost as their initial therapy were more likely to adhere and persist to the index PGA compared with bimatoprost users. The latanoprost group demonstrated a lower risk of discontinuing first-line therapy than the travoprost and bimatoprost groups. The results may assist ophthalmologists in determining the optimal management of this patient population with respect to treatment patterns. DISCLOSURES: No outside funding supported this study. All authors except Heo and Nair are employed by The University of Texas at Austin College of Pharmacy. Heo was with the Health Outcomes Division, The University of Texas at Austin College of Pharmacy during a portion of this study and is employed by Genesis Research. Nair is employed by Humana. The authors have no financial relationships relevant to this article to disclose. This study was presented as a poster at the 2016 International Society for Pharmacoeconomics and Outcomes Research Annual Meeting, May 2016, Washington, DC.

Increased Fracture Risk with Furosemide Use in Children with Congenital Heart Disease.

OBJECTIVES: To determine the association of furosemide therapy with the incidence of bone fractures in children with congenital heart disease. STUDY DESIGN: We conducted a retrospective cohort study with data extracted from the 2008-2014 Texas Medicaid databases. Pediatric patients aged <12 years diagnosed with congenital heart disease, cardiomyopathy, or heart failure were included. Patients taking furosemide were categorized into a furosemide-adherent group (medication possession ratio of ≥70%), and a furosemide-nonadherent group (medication possession ratio of <70%). A third group of patients was matched to the furosemide user groups by using propensity score matching. A multivariate logistic regression and Cox proportional hazard model with a Kaplan-Meier plot (time-to-fracture) were used to compare the 3 groups, controlling for baseline demographics and clinical characteristics. RESULTS: After matching, 3912 patients (furosemide adherent, n = 254; furosemide nonadherent, n = 724; no furosemide, n = 2934) were identified. The incidence of fractures was highest for the furosemide-adherent group (9.1%; 23 of 254), followed by the furosemide-nonadherent group (7.2%; 52 of 724), which were both higher than for patients who did not receive furosemide (5.0%; 148 of 2934) (P < .001). Using logistic regression, both furosemide groups were more likely to have fractures than the no furosemide group: furosemide-adherent OR of 1.9 (95% CI, 1.17-2.98; P = .009); furosemide nonadherent OR of 1.5 (95% CI, 1.10-2.14; P = .01). In the Cox proportional hazard model, the risk of fractures for the furosemide-adherent group was significantly higher compared with the no furosemide group (HR, 1.6; 95% CI, 1.00-2.42; P = .04). CONCLUSIONS: Furosemide therapy, even with nonconsistent dosing, was associated with an increased risk of bone fractures in children with congenital heart disease.

Prediction of Change in Prescription Ingredient Costs and Co-payment Rates under a Reference Pricing System in South Korea.

BACKGROUND: The reference pricing system (RPS) establishes reference prices within interchangeable reference groupings. For drugs priced higher than the reference point, patients pay the difference between the reference price and the total price. OBJECTIVES: To predict potential changes in prescription ingredient costs and co-payment rates after implementation of an RPS in South Korea. METHODS: Korean National Health Insurance claims data were used as a baseline to develop possible RPS models. Five components of a potential RPS policy were varied: reference groupings, reference pricing methods, co-pay reduction programs, manufacturer price reductions, and increased drug substitutions. The potential changes for prescription ingredient costs and co-payment rates were predicted for the various scenarios. RESULTS: It was predicted that transferring the difference (total price minus reference price) from the insurer to patients would reduce ingredient costs from 1.4% to 22.8% for the third-party payer (government), but patient co-payment rates would increase from a baseline of 20.4% to 22.0% using chemical groupings and to 25.0% using therapeutic groupings. Savings rates in prescription ingredient costs (government and patient combined) were predicted to range from 1.6% to 13.7% depending on various scenarios. Although the co-payment rate would increase, a 15% price reduction by manufacturers coupled with a substitution rate of 30% would result in a decrease in the co-payment amount (change in absolute dollars vs. change in rates). CONCLUSIONS: Our models predicted that the implementation of RPS in South Korea would lead to savings in ingredient costs for the third-party payer and co-payments for patients with potential scenarios.

Evaluation of the pilot program on the real-time drug utilization review system in South Korea.

PURPOSE: A pilot drug utilization review (DUR) program was initiated by the Korean government, which provided safety information in real-time at the stage of prescribing and dispensing. This study aimed to compare the "physician/pharmacist Co-DUR" system and the traditional "pharmacist-only DUR" system. METHODS: Data collected during a DUR pilot program from July 1 to October 31 of 2009 were obtained from the Health Insurance Review & Assessment Service. Descriptive analyses were conducted to investigate DUR-pop up alert rates, categories of alerts, the reasons for dispensing without prescription change after an alert, and changes in drug expenditures associated with the DUR. RESULTS: DUR pop-up alert rates were 8.55% at clinics and 1.90% at pharmacies in the physician/pharmacist Co-DUR, whereas the rate was 2.22% in the pharmacist-only DUR. Rates of pop-up alerts were high for between-prescription ingredient duplication at pharmacies, whereas for clinics, the rate for drug-pregnancy contraindications was high. A greater reduction in drug expenditure was estimated in the physician/pharmacist Co-DUR compared to the pharmacist-only DUR. CONCLUSIONS: The physician/pharmacist Co-DUR has better sensitivity at detecting potential adverse drug events than the pharmacist-only DUR. Pharmacists also have opportunities to double-check prescribed drugs when doctors do not voluntarily modify pop-up alerts. Further comprehensive study will be needed to confirm the results of pilot program that favored the physician/pharmacist Co-DUR.

Directly Pd(II)-bridged porphyrin belts with remarkable curvatures.

A beta,beta'-doubly 2,6-pyridylene-bridged porphyrin dimer and trimer were prepared by Suzuki-Miyaura coupling reactions and confirmed to have largely bent structures. These oligoporphyrins were readily metalated via meso-C-H bond activation with the assistance of the pyridyl nitrogen atoms to produce the corresponding Pd(II) complexes, which display even larger bent structures and larger TPA values at 800 nm.

Molecular-shape-dependent photophysical properties of meso-ß doubly linked Zn(II) porphyrin arrays and their indene-fused analogues.

meso-ß doubly linked Zn(II) porphyrin arrays and their indene-fused analogues were prepared by Suzuki-Miyaura coupling and subsequent oxidation with DDQ-Sc(OTf)(3). The excited state properties of these conjugated porphyrin arrays have been investigated by steady-state and time-resolved spectroscopy along with quantum mechanical calculations to reveal their molecular shape dependencies with respect to syn- versus anti-connectivity as well as nonfused versus fused structures. Nonfused syn-trimer exhibits nearly the same S(1)-state lifetime and two-photon absorption (TPA) value as the nonfused dimer, while the nonfused anti-trimer exhibits different values. The TD-DFT calculations also demonstrate that the nonfused anti-trimer has a different electronic structure from the corresponding syn-trimer. Indene-fused dimers and trimers exhibit the enhanced TPA values and shortened S(1)-state lifetime because of the elongated π-conjugation and the perturbation of electronic structures. Our research provides further insight into the molecular-shape-dependent electronic properties of meso-ß doubly linked Zn(II) porphyrin arrays.