COmparing Urolift and Standard Transurethral resection of prostate Ahead of Radiotherapy in men with urinary symptoms secondary to prostate enlargement in Southwest London and North Cumbria (CO-STAR): a study protocol for a randomised feasibility study.

INTRODUCTION: Patients undergoing prostate radiotherapy with an enlarged prostate can have short-term and long-term urinary complications. Currently, transurethral resection of the prostate (TURP) is the mainstay surgical intervention for men with urinary symptoms due to an enlarged prostate prior to radiotherapy. UroLift (NeoTract, Pleasanton, CA, USA) is a recent minimally invasive alternative, widely used in benign disease but is untested in men with prostate cancer. METHODS AND ANALYSIS: A multicentre, two-arm study designed in collaboration with a Patient Reference Group to assess the feasibility of randomising men with prostate cancer and coexisting urinary symptoms due to prostate enlargement to TURP or UroLift ahead of radiotherapy. 45 patients will be enrolled and randomised (1:1) using a computer-generated programme to TURP or UroLift. Recruitment and retention will be assessed over a 12 month period. Information on clinical outcomes, adverse events and costs will be collected. Clinical outcomes and patient reported outcome measures will be measured at baseline, 6 weeks postintervention and 3 months following radiotherapy. A further 12 in-depth interviews will be conducted with a subset of patients to assess acceptability using the Theoretical Framework of Acceptability. Descriptive analysis on all outcomes will be performed using Stata (StataCorp V.2021). ETHICS AND DISSEMINATION: The trial has been approved by the Research Ethics Committee (REC) NHS Health Research Authority (HRA) and Health and Care Research Wales (HCRW). The results will be published in peer-reviewed journals, presented at national meetings and disseminated to patients via social media, charity and hospital websites. TRIAL REGISTRATION NUMBER: NCT05840549.

Predicting the Need for Biopsy to Detect Clinically Significant Prostate Cancer in Patients with a Magnetic Resonance Imaging-detected Prostate Imaging Reporting and Data System/Likert ≥3 Lesion: Development and Multinational External Validation of the Imperial Rapid Access to Prostate Imaging and Diagnosis Risk Score.

BACKGROUND: Although multiparametric magnetic resonance imaging (MRI) has high sensitivity, its lower specificity leads to a high prevalence of false-positive lesions requiring biopsy. OBJECTIVE: To develop and externally validate a scoring system for MRI-detected Prostate Imaging Reporting and Data System (PIRADS)/Likert ≥3 lesions containing clinically significant prostate cancer (csPCa). DESIGN, SETTING, AND PARTICIPANTS: The multicentre Rapid Access to Prostate Imaging and Diagnosis (RAPID) pathway included 1189 patients referred to urology due to elevated age-specific prostate-specific antigen (PSA) and/or abnormal digital rectal examination (DRE); April 27, 2017 to October 25, 2019. INTERVENTION: Visual-registration or image-fusion targeted and systematic transperineal biopsies for an MRI score of ≥4 or 3 + PSA density ≥0.12 ng/ml/ml. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Fourteen variables were used in multivariable logistic regression for Gleason ≥3 + 4 (primary) and Gleason ≥4 + 3, and PROMIS definition 1 (any ≥4 + 3 or ≥6 mm any grade; secondary). Nomograms were created and a decision curve analysis (DCA) was performed. Models with varying complexity were externally validated in 2374 patients from six international cohorts. RESULTS AND LIMITATIONS: The five-item Imperial RAPID risk score used age, PSA density, prior negative biopsy, prostate volume, and highest MRI score (corrected c-index for Gleason ≥3 + 4 of 0.82 and 0.80-0.86 externally). Incorporating family history, DRE, and Black ethnicity within the eight-item Imperial RAPID risk score provided similar outcomes. The DCA showed similar superiority of all models, with net benefit differences increasing in higher threshold probabilities. At 20%, 30%, and 40% of predicted Gleason ≥3 + 4 prostate cancer, the RAPID risk score was able to reduce, respectively, 11%, 21%, and 31% of biopsies against 1.8%, 6.2%, and 14% of missed csPCa (or 9.6%, 17%, and 26% of foregone biopsies, respectively). CONCLUSIONS: The Imperial RAPID risk score provides a standardised tool for the prediction of csPCa in patients with an MRI-detected PIRADS/Likert ≥3 lesion and can support the decision for prostate biopsy. PATIENT SUMMARY: In this multinational study, we developed a scoring system incorporating clinical and magnetic resonance imaging characteristics to predict which patients have prostate cancer requiring treatment and which patients can safely forego an invasive prostate biopsy. This model was validated in several other countries.

A Comparison of Prostate Cancer Detection between Visual Estimation (Cognitive Registration) and Image Fusion (Software Registration) Targeted Transperineal Prostate Biopsy.

PURPOSE: We compared clinically significant prostate cancer detection by visual estimation and image fusion targeted transperineal prostate biopsy. MATERIALS AND METHODS: This multicenter study included patients with multiparametric magnetic resonance imaging lesions undergoing visual estimation or image fusion targeted transperineal biopsy (April 2017-March 2020). Propensity score matching was performed using demographics (age and ethnicity), clinical features (prostate specific antigen, prostate volume, prostate specific antigen density and digital rectal examination), multiparametric magnetic resonance imaging variables (number of lesions, PI-RADS® score, index lesion diameter, whether the lesion was diffuse and radiological T stage) and biopsy factors (number of cores, operator experience and anesthetic type). Matched groups were compared overall and by operator grade, PI-RADS score, lesion multiplicity, prostate volume and anesthetic type using targeted-only and targeted plus systematic histology. Multiple clinically significant prostate cancer thresholds were evaluated (primary: Gleason ≥3+4). RESULTS: A total of 1,071 patients with a median age of 67.3 years (IQR 61.3-72.4), median prostate specific antigen of 7.5 ng/ml (IQR 5.3-11.2) and 1,430 total lesions underwent targeted-only biopsies (visual estimation: 372 patients, 494 lesions; image fusion: 699 patients, 936 lesions). A total of 770 patients with a median age of 67.4 years (IQR 61-72.1), median prostate specific antigen of 7.1 ng/ml (IQR 5.2-10.6) and 919 total lesions underwent targeted plus systematic biopsies (visual estimation: 271 patients, 322 lesions; image fusion: 499 patients, 597 lesions). Matched comparisons demonstrated no overall difference in clinically significant prostate cancer detection between visual estimation and image fusion (primary: targeted-only 54% vs 57.4%, p=0.302; targeted plus systematic 51.2% vs 58.2%, p=0.123). Senior urologists had significantly higher detection rates using image fusion (primary: targeted-only 45.4% vs 63.7%, p=0.001; targeted plus systematic 39.4% vs 64.5%, p <0.001). CONCLUSIONS: We found no overall difference in clinically significant prostate cancer detection, although image fusion may be superior in experienced hands.

Initial outcomes of local anaesthetic freehand transperineal prostate biopsies in the outpatient setting.

OBJECTIVES: To evaluate the histopathological outcomes, morbidity and tolerability of freehand transperineal (TP) prostate biopsies using the PrecisionPoint™ access system (Perineologic, Cumberland, MD, USA) under local anaesthetic (LA) in the day surgery and outpatient environments, as systematic and targeted biopsies can be taken with the potential for reduced morbidity, particularly sepsis. PATIENTS AND METHODS: In all, 176 patients underwent freehand TP prostate biopsies from May 2016 to November 2017. The procedure was carried out either under LA alone or with the addition of sedation. Magnetic resonance imaging (MRI) scans were reported using the Prostate Imaging-Reporting and Data System (PI-RADS), version 2. Tolerability was assessed using a visual analogue scale pain score for each procedural stage. Histopathological outcomes and complications were recorded. RESULTS: The mean (range) age was 65 (36-83) years, median (range) prostate-specific antigen level was 7.9 (0.7-1374) ng/mL, and the mean (range) prostate volume 45 (15-157) mL. Biopsies were taken under LA alone (160 patients, 90%) or under LA with sedation (16, 9%). The main indication for biopsy was primary diagnosis (88.6%). In all, 91 (52%) patients underwent systematic TP biopsies (mean 24.2 cores). Cognitive MRI-targeted biopsies alone were performed in 45 patients (26%; mean 6.8 cores), and 40 (23%) had both systematic and target biopsies (mean 27.9 cores). Of the 75 patients who had primary systematic biopsies alone, 46 (61%) were positive, and 28/46 (60.9%) were diagnosed with clinically significant disease (Gleason ≥3+4). VAS pain scores were greatest during LA administration. There were five complications (2.8%, Clavien-Dindo Grade I/II). No patients developed urosepsis. CONCLUSIONS: Freehand TP biopsies using the PrecisionPoint access system is a safe, tolerable and effective method for systematic and targeted biopsies under LA in the outpatient setting. It has replaced transrectal biopsies in our centre and has potential to transform practice.

Hypertension and renal impairment in patients with cystinuria: findings from a specialist cystinuria centre.

Higher blood pressures (mean systolic difference 16.8 mmHg) when compared to matched individuals are already reported in patients with calcium urolithiasis. We present the prevalence of hypertension and renal impairment in patients with cystinuria from our specialist single centre. We analysed our prospective database of adult patients with cystinuria who attend our cystinuria service. This included details of the medical and operative management of their disease. Descriptive statistics were used to analyse and present the data. 120 patients were included with a median age of 40 (19-76) years, 66 were male (55%) and 54 were female (45%). 54/120 patients (45%) were taking medications to prevent stone formation. 78% (94/120) patients reported having undergone one or more stone-related procedure. 59% (55/94) of these having required at least one PCNL or open procedure during their lifetime. Prevalence of hypertension was 50.8% (61/120), and double in males compared to females (62.1% vs. 37.0%, P = 0.0063). Mean baseline creatinine was 88.2 (49-153) µmol/l and eGFR was 77.6 (32-127) ml/min/1.73 m2. When categorized by CKD stage, only 24.6% (27% vs. 21%, M vs. F) patients had normal renal function (being an eGFR > 89 ml/min/1.73 m2). 57.6% patients were CKD stage 2 and 17.8% CKD stage 3. Females had a slightly greater incidence of renal impairment. All patients who have previously undergone a nephrectomy (n = 10) or have a poorly functioning kidney (n = 19) have renal impairment (CKD stage 2 or 3). Incidence of hypertension in patients with cystinuria is 51%, with a male preponderance. Only 25% of patients with cystinuria have normal renal function. This highlights the long-term cardiovascular and renal risks that the metabolic effects of cystinuria pose, in addition to the challenges of managing recurrent urolithiasis in a young population.

Associating mutations causing cystinuria with disease severity with the aim of providing precision medicine.

BACKGROUND: Cystinuria is an inherited disease that results in the formation of cystine stones in the kidney, which can have serious health complications. Two genes (SLC7A9 and SLC3A1) that form an amino acid transporter are known to be responsible for the disease. Variants that cause the disease disrupt amino acid transport across the cell membrane, leading to the build-up of relatively insoluble cystine, resulting in formation of stones. Assessing the effects of each mutation is critical in order to provide tailored treatment options for patients. We used various computational methods to assess the effects of cystinuria associated mutations, utilising information on protein function, evolutionary conservation and natural population variation of the two genes. We also analysed the ability of some methods to predict the phenotypes of individuals with cystinuria, based on their genotypes, and compared this to clinical data. RESULTS: Using a literature search, we collated a set of 94 SLC3A1 and 58 SLC7A9 point mutations known to be associated with cystinuria. There are differences in sequence location, evolutionary conservation, allele frequency, and predicted effect on protein function between these mutations and other genetic variants of the same genes that occur in a large population. Structural analysis considered how these mutations might lead to cystinuria. For SLC7A9, many mutations swap hydrophobic amino acids for charged amino acids or vice versa, while others affect known functional sites. For SLC3A1, functional information is currently insufficient to make confident predictions but mutations often result in the loss of hydrogen bonds and largely appear to affect protein stability. Finally, we showed that computational predictions of mutation severity were significantly correlated with the disease phenotypes of patients from a clinical study, despite different methods disagreeing for some of their predictions. CONCLUSIONS: The results of this study are promising and highlight the areas of research which must now be pursued to better understand how mutations in SLC3A1 and SLC7A9 cause cystinuria. The application of our approach to a larger data set is essential, but we have shown that computational methods could play an important role in designing more effective personalised treatment options for patients with cystinuria.

How can cardiothoracic and vascular medical devices stay in the market?

Surgeons, as the consumers, must engage in commercial activity regarding medical devices since it directly has impacts on surgical practice and patient outcomes. Unique features defy traditional economic convention in this specific market partly because consumers do not usually pay directly. Greater involvement with commercial activity means better post-market surveillance of medical devices which leads to improved patient safety. The medical device industry has exhibited astonishing levels of growth and profitability reaching $398 billion on a global scale with new product development focusing on unmet clinical need. The industry has rapidly emerged within the context of an ageing population and a global surge in healthcare spending. But the market remains fragmented. The split of consumer, purchaser and payer leads to clinical need driving demand for new product development. This demand contributes to potentially large profit margins mainly contained by regulatory burden and liability issues. Demographic trends, prevalence of diseases and a huge capacity to absorb technology have sustained near unparalleled growth. To stay in the market, incremental development over the short term is essentially aided by responsiveness to demand. Disruptive product development is now more likely to come from multinational companies, in an increasingly expensive, regulated industry. Understanding healthcare organization can help explain the highly complex process of diffusion of innovations in healthcare that include medical devices. The time has come for surgeons to become actively involved with all aspects of the medical device life cycle including commercial activity and post-market surveillance. This is vital for improving patient care and ensuring patient safety.

Can the Presence of Crystalluria Predict Stone Formation in Patients with Cystinuria?

OBJECTIVES: To determine the feasibility of crystalluria as a biomarker for stone disease in patients with cystinuria. PATIENTS AND METHODS: All patients attending a multidisciplinary cystinuria clinic provided early morning urine (EMU) and clinic urine (CU) samples for crystal measurement over a 2-year period (August 1, 2010, to July 31, 2012). Association between presence of crystals, presence of stone(s), and new stone growth (NSG) was determined using the chi-square test. Crystal numbers in EMU and CU were compared in patients with stones/NSG and no stones/stable disease using the Mann-Whitney U test. RESULTS: There was a statistically significant difference between the presence of crystalluria and presence of stones for CU (chi-square test = 5.86, df = 1, p = 0.02) but not EMU (chi-square test = 1.92, df = 1, p = 0.17) and between the presence of crystalluria and NSG for CU (chi-square test = 8.10, df = 1, p = 0.004) but not EMU (chi-square test = 1.32, df = 1, p = 0.25). Patients with stones and NSG have higher levels of crystalluria in CU than patients with no stones or stable disease (stones, median = 41, interquartile range [IQR] = 600 vs median = 0, IQR = 21, p = 0.01; NSG, median = 49, IQR = 525 vs median = 0, IQR = 40, p = 0.01). CONCLUSION: The presence of crystalluria in CU samples is associated with the presence of stones. Crystalluria is comparable to ultrasound and may serve as a useful adjunct to predict whether a patient with cystinuria has stones, which could guide the frequency of clinic review and imaging.

The genetic diversity of cystinuria in a UK population of patients.

OBJECTIVE: To examine the genetic mutations in the first UK cohort of patients with cystinuria with preliminary genotype/phenotype correlation. PATIENTS AND METHODS: DNA sequencing and multiplex ligation-dependent probe amplification (MLPA) were used to identify the mutations in 74 patients in a specialist cystinuria clinic in the UK. Patients with type A cystinuria were classified into two groups: Group M patients had at least one missense mutation and Group N patients had two alleles of all other types of mutations including frameshift, splice site, nonsense, deletions and duplications. The levels of urinary dibasic amino acids, age at presentation of disease, number of stone episodes and interventions were compared between patients in the two groups using the Mann-Whitney U-test. RESULTS: In all, 41 patients had type A cystinuria, including one patient with a variant of unknown significance and 23 patients had type B cystinuria, including six patients with variants of unknown significance. One patient had three sequence variants in SLC7A9; however, two are of unknown significance. Three patients had type AB cystinuria. Three had a single mutation in SLC7A9. No identified mutations were found in three patients in either gene. There were a total of 88 mutations in SLC3A1 and 55 mutations in SLC7A9. There were 23 pathogenic mutations identified in our UK cohort of patients not previously published. In patients with type A cystinuria, the presence of a missense mutation correlated to lower levels of urinary lysine (mean [SE] 611.9 [22.65] vs 752.3 [46.39] millimoles per mole of creatinine [mM/MC]; P=0.02), arginine (194.8 [24.83] vs 397.7 [15.32] mM/MC; P<0.001) and ornithine (109.2 [7.40] vs 146.6 [12.7] mM/MC; P=0.02). There was no difference in the levels of urinary cystine (182.1 [8.89] vs 207.2 [19.23] mM/MC; P=0.23). CONCLUSIONS: We have characterised the genetic diversity of cystinuria in a UK population including 23 pathogenic mutations not previously published. Patients with at least one missense mutation in SLC3A1 had significantly lower levels of lysine, arginine, and ornithine but not cystine than patients with all other combinations of mutations.

Cystinuria-a urologist's perspective.

Cystinuria is a genetic disease that leads to frequent formation of stones. In patients with recurrent stone formation, particularly patients <30 years old or those who have siblings with stone disease, urologists should maintain a high index of suspicion of the diagnosis of cystinuria. Patients with cystinuria require frequent follow-up and a multidisciplinary approach to diagnosis, prevention and management. Patients have reported success in preventing stone episodes by maintaining dietary changes using a tailored review from a specialist dietician. For patients who do not respond to conservative lifestyle measures, medical therapy to alkalinize urine and thiol-binding drugs can help. A pre-emptive approach to the surgical management of cystine stones is recommended by treating smaller stones with minimally invasive techniques before they enlarge to a size that makes management difficult. However, a multimodal approach can be required for larger complex stones. Current cystinuria research is focused on methods of monitoring disease activity, novel drug therapies and genotype-phenotype studies. The future of research is collaboration at a national and international level, facilitated by groups such as the Rare Kidney Stone Consortium and the UK Registry of Rare Kidney Diseases.

Outpatient laser ablation of non-muscle-invasive bladder cancer: is it safe, tolerable and cost-effective?

OBJECTIVES: To evaluate the safety, tolerability and effectiveness of outpatient (office-based) laser ablation (OLA), with local anaesthetic, for non-muscle-invasive bladder cancer (NMIBC) in an elderly population with and without photodynamic diagnosis (PDD). To compare the cost-effectiveness of OLA of NMIBC with that of inpatient cystodiathermy (IC). PATIENTS AND METHODS: We conducted a prospective cohort study of patients with NMIBC treated with OLA by one consultant surgeon between March 2008 and July 2011 A subgroup of patients had PDD before undergoing OLA. Safety and effectiveness were determined by complications (In the immediate post operative period, at three days and at three months), patient tolerability (visual analogue score) and recurrence rates. The long-term costs and cost-effectiveness of OLA and IC of NMIBC were evaluated using Markov modeling. RESULTS: A total of 74 OLA procedures (44 white-light, 30 PDD) were carried out in 54 patients. The mean (range) patient age was 77 (52-95) years. More than half of the patients had more than three comorbidities. Previous tumour histology ranged from G1pTa to T3. One patient had haematuria for 1 week which settled spontaneously and did not require hospital admission. There were no other complications. The procedure was well tolerated with pain scores of 0-2/10. Additional lesions were found in 21% of patients using PDD that were not found using white light. At 3 months, the percentage of patients who had recurrence after OLA with white light and OLA with PDD were 10.6 and 4.3%, respectively. At 1 year, 65.1% and 46.9% of patients had recurrence. The cost of OLA was found to be much lower than that of IC (£538 vs £1474), even with the addition of PDD (£912 vs £1844). Over the course of a patient's lifetime, OLA was more clinically effective, measured in quality-adjusted life-years (QALY), than IC (0.147 [sd 0.059]) and less costly (£2576.42 [sd £7293.07]). At a cost-effectiveness threshold of £30,000/QALY, as set by the National Institute for Health and Care Excellence, there was an 82% probability that OLA was cost-effective. CONCLUSIONS: This is the first study to demonstrate the long-term cost-effectiveness of OLA of NMIBC. The results support the use of OLA for the treatment of NMIBC, especially in the elderly.

Management of stones in renal transplant.

PURPOSE OF REVIEW: Increasingly, screening of both deceased and living donor organs has led to the early detection of kidney stones prior to donation. A number of transplant recipients will still present with donor-gifted and de-novo stones. A range of treatment modalities is available in the management of renal transplant stones. RECENT FINDINGS: Stones can be pretreated in the (living) donor prior to transplantation, managed at the time of transplantation or treated in the recipient post-transplant. The options include conservative management, extracorporeal shockwave lithotripsy, percutaneous nephrolithotomy, ureteroscopy or open surgery depending on the size and location of the stone(s). Various techniques to deal with a transplant kidney are described. Ex-vivo ureteroscopy or pyeloscopy can safely render a kidney-stone free prior to transplantation and in living donors this means without subjecting the living donor to an additional stone removing procedure. SUMMARY: The cause of renal transplant lithiasis is multifactorial. More research is needed to understand the factors associated with de-novo stone formation. Early detection of donor-gifted stones can allow stones to be removed at the time of transplantation. Close follow up of both living donors and transplant recipients is necessary to ensure long-term safety is maintained.

Incidental renal stones in potential live kidney donors: prevalence, assessment and donation, including role of ex vivo ureteroscopy.

UNLABELLED: WHAT'S KNOWN ON THE SUBJECT? AND WHAT DOES THE STUDY ADD?: Previously, donors with asymptomatic stones found incidentally on CT were not considered ideal donor candidates because of the presumed risk of morbidity to both the donor and recipient. Increasingly, studies show that these risks are low. This study aims to evaluate the long-term safety of using ex vivo ureteroscopy to remove the stones from the donor kidney on the bench before donation. Outcomes so far suggest that this technique can safely render a kidney stone-free before transplantation. This has led to 20 more transplants in our institution than would otherwise be possible. OBJECTIVES: To evaluate the prevalence of asymptomatic renal stones in our potential donor population. To assess the safety and success of ex vivo ureteroscopy (ExURS) to remove stones from explanted donor kidneys before transplantation. PATIENTS AND METHODS: We conducted a retrospective analysis of 377 computed tomography (CT) angiograms of potential kidney donors between October 2004 and May 2007 to assess the prevalence of asymptomatic renal stones in our donor population. Between October 2005 and October 2011, kidneys from suitable donors underwent ExURS. Stones were removed using basket extraction or were fragmented with holmium laser on bench before transplantation. Immediate and long-term complications of the transplanted recipients were recorded. Donors were followed with yearly ultrasonography of the remaining kidney in addition to standard follow-up protocol. RESULTS: Review of 377 CT angiograms between October 2004 to May 2007 showed a 5% prevalence of asymptomatic renal stones. Out of 55 potential donors (19 identified between October 2004 to May 2007 and a further 36 identified since May 2007), 20 donors with stones proceeded to donation, with stone size ranging from 2 to 12 mm. Of the patients, 17 proceeded to ExURS. Stones were removed in 10 patients; five with basket retrieval, four with laser fragmentation and one with both laser fragmentation and basket retrieval. There were no early or late allograft stone-related complications and no evidence of stones on follow-up imaging at a mean (range) of 10 (1-24) months. There has been no reported stone recurrence in any of the donors to date and no stone on ultrasonography of eight donors with >1-year follow-up (mean 26 months, range 12-49 months). CONCLUSIONS: Asymptomatic renal stones are present in 5% of our donors. ExURS can be safely used to remove stones in these kidneys before transplantation, without the risk of subjecting the donor to an additional stone-removing procedure. Continued long-term follow-up of donors and recipients is still required to ensure the safety of this approach.

Leadership in cardiac surgery.

Despite the efficacy of cardiac surgery, less invasive interventions with more uncertain long-term outcomes are increasingly challenging surgery as first-line treatment for several congenital, degenerative and ischemic cardiac diseases. The specialty must evolve if it is to ensure its future relevance. More importantly, it must evolve to ensure that future patients have access to treatments with proven long-term effectiveness. This cannot be achieved without dynamic leadership; however, our contention is that this is not enough. The demands of a modern surgical career and the importance of the task at hand are such that the serendipitous emergence of traditional charismatic leadership cannot be relied upon to deliver necessary change. We advocate systematic analysis and strategic leadership at a local, national and international level in four key areas: Clinical Care, Research, Education and Training, and Stakeholder Engagement. While we anticipate that exceptional individuals will continue to shape the future of our specialty, the creation of robust structures to deliver collective leadership in these key areas is of paramount importance.

Cardioprotection by the female sex hormone -- interaction with the beta1-adrenoceptor and its signaling pathways.

Estrogen is a steroid and the predominant female sex hormone in the body. Ovariectomised (OVX) adult female rats exhibit greater myocardial injury compared to the sham rats following ischemic insult in the presence of beta-adrenoceptor stimulation. Estrogen replacement restores the response of OVX female rats to ischemic/beta-adrenoceptor stimulation to that of normal female rats, providing evidence for a cardioprotective role of estrogen during ischemic insult. The protective effect is due to down-regulation of the beta(1)-adrenoceptor. There is also evidence that estrogen suppresses the expression and activity of protein kinase A (PKA), a second messenger of the G(s) protein/adenylyl cyclase/cAMP/PKA pathway which ultimately influences contractile function. There is also preliminary evidence that estrogen may suppress the activity of Ca(2+)/calmodulin kinase II deltac isoform (CaMKII-deltac), another downstream second messenger of the beta(1)-adrenoceptor pathway, which is involved in PKA-independent cell apoptosis. Acute administration of estrogen at physiological level could inhibit myocardial beta(1)-adrenoceptor and attenuate Ca(2+) influx independent of the estrogen receptor. In addition, brain studies also show estrogen inhibits the activities activated by the beta-adrenoceptor in brain regions responsible for the regulation of arterial blood pressure. Thus, it can be appreciated that the interaction between estrogen and the beta(1)-adrenoceptor and its signaling pathways is a complex one. Estrogen plays an important role not only in reproduction but also in other regulatory functions such as cardioprotection.