Comparison of outcomes of percutaneous MitraClip versus surgical repair or replacement for degenerative mitral regurgitation in octogenarians

Stroke Risk After Mitral Valve Interventions: A Systematic Review and Network Meta-Analysis

Previous research indicates varying stroke rates after mitral valve (MV) interventions. This study aimed to compare postprocedural stroke risks after transcatheter and surgical MV interventions. Electronic databases were searched from inception to February 2024 for studies comparing stroke rates after mitral transcatheter edge-to-edge repair (mTEER), surgical MV repair/replacement, or guideline-directed medical therapy (GDMT). Primary end points were all-time and early (<30 days) stroke. Secondary outcomes included new-onset atrial fibrillation and 1-year all-cause mortality. A frequentist network meta-analysis was employed to compare outcomes. The network meta-analysis included 18 studies (3 randomized controlled trials and 15 observational), with 51,703 patients. mTEER was associated with a decreased risk of all-time (odds ratio [OR] 0.61, 95% confidence interval [CI] 0.41 to 0.89) and early stroke (OR 0.41, 95% CI 0.33 to 0.51) compared with surgery, and a similar risk of all-time (OR 1.54, 95% CI 0.76 to 3.12) and early stroke (OR 2.12, 95% CI 0.53 to 8.47) compared with GDMT. Conversely, surgery was associated with an increased risk of all-time (OR 2.55, 95% CI 1.17 to 5.57) and early stroke (OR 5.15, 95% CI 1.27 to 20.84) compared with GDMT. There were no statistically significant differences in the risk of new-onset atrial fibrillation (OR 0.38, 95% CI 0.11 to 1.31) and 1-year all-cause mortality (OR 1.43, 95% CI 0.91 to 2.24) between mTEER versus surgery. In conclusion, mTEER was associated with a lower risk of stroke and similar risks of new-onset atrial fibrillation and 1-year mortality compared with surgical MV interventions. Further studies are needed to understand the mechanisms of stroke and to determine strategies to reduce stroke risk after MV interventions.

Mortality and morbidity of surgical and transcatheter mitral valve repair in octogenarians: A systematic review

BACKGROUND

Valvular heart disease (VHD) is a prominent problem in healthcare today with mitral regurgitation (MR) being the leading cause of VHD in the elderly population. While mitral valve repair (MVr) surgery is one of the only options for the end-stage disease, octogenarians are often denied MVr due to concerns with operative mortality and postoperative morbidity. To provide information on this underrepresented group of surgical patients, a systematic approach was taken to review the mortality and morbidity rates of octogenarians who received MVr.

METHODS

Pubmed and Medline were searched for articles containing outcomes of octogenarians receiving surgical mitral valve repair (SMVr) or transcatheter mitral valve repair (TMVr) published after 2000. Ten articles met the inclusion criteria for a total of 7968 patients included in the analysis using Microsoft Excel, Version 2105.

RESULTS

Short-term mortality rates for SMVr and TMVr were 2.6% and 1.4% for in-hospital, and 7.8% and 3.3% for 30 days, respectively. The average incidence of stroke, acute kidney injury, infection, and major bleeding for SMVr were 3.2%, 11.2%, 7.7%, and 24%, respectively, and 0.3%, 6.7%, 2.7%, and 7.9% for TMVr, respectively.

CONCLUSION

Octogenarians receiving SMVr or TMVr experienced similar rates of short-term mortality and morbidity as younger populations, and when considering life expectancy, midterm mortality was also similar. With these results, denying octogenarians MVr operations based on age alone should be reconsidered. Depending on risk factors and comorbidities, either SMVr or TMVr is a viable and relatively safe option for octogenarians with severe MR.

Transcatheter Versus Surgical Valve Repair in Patients with Severe Mitral Regurgitation

Background. Transcatheter edge-to-edge mitral valve repair (TMVR) is increasingly performed. However, its efficacy in comparison with surgical MV treatment (SMV) is unknown. Methods. Consecutive patients with severe mitral regurgitation (MR) undergoing TMVR (68% functional, 32% degenerative) or SMV (9% functional, 91% degenerative) were enrolled. To account for differences in baseline characteristics, propensity score matching was performed, including age, EuroSCORE-II, left ventricular ejection fraction, and NT-proBNP. A composite of heart failure (HF) hospitalization/death served as primary endpoint. Kaplan-Meier curves and Cox-regression analyses were used to investigate associations between baseline, imaging, and procedural parameters and outcome. Results. Between July 2017 and April 2020, 245 patients were enrolled, of whom 102 patients could be adequately matched (73 y/o, 61% females, EuroSCORE-II: 5.7%, p > 0.05 for all). Despite matching, TMVR patients had more co-morbidities at baseline (higher rates of prior myocardial infarction, coronary revascularization, pacemakers/defibrillators, and diabetes mellitus, p < 0.009 for all). Patients were followed for 28.3 ± 27.2 months, during which 27 events (17 deaths, 10 HF hospitalizations) occurred. Postprocedural MR reduction (MR grade <2: TMVR vs. SMV: 88% vs. 94%, p = 0.487) and freedom from HF hospitalization/death (log-rank: p = 0.811) were similar at 2 years. On multivariable Cox analysis, EuroSCORE-II (adj.HR 1.07 [95%CI: 1.00–1.13], p = 0.027) and residual MR (adj.HR 1.85 [95%CI: 1.17–2.92], p = 0.009) remained significantly associated with outcome. Conclusions. In this propensity-matched, all-comers cohort, two-year outcomes after TMVR versus SMV were similar. Given the reported favorable long-term durability of TMVR, the interventional approach emerges as a valuable alternative for a substantial number of patients with functional and degenerative MR.

Mitral and Tricuspid Valves Percutaneous Repair in Patients with Advanced Heart Failure: Panacea, or Pandora's Box?

In heart failure with reduced ejection fraction, the interventional landscape has recently expanded. New transcatheter approaches are emerging for both mitral and tricuspid secondary (functional) regurgitation. Transcatheter therapies for mitral and tricuspid valve require a more tailored approach than for the aortic valve, because of more heterogeneous clinical scenarios, anatomic features, and mechanisms of valvular lesions.

Characteristics and outcomes of MitraClip in octogenarians: Evidence from 1853 patients in the GIOTTO registry

BACKGROUND

We aimed at appraising features and outcomes of patients undergoing MitraClip treatment according to their age.

METHODS

We queried the prospective GIse registry Of Transcatheter treatment of mitral valve regurgitaTiOn (GIOTTO) multicenter registry dataset including 19 Italian centers performing MitraClip implantation, distinguishing patients <80 vs ≥80 years of age.

RESULTS

In total, 1853 patients were included, 751 (40.5%) octogenarians and 1102 (59.5%) non-octogenarians. Several baseline and procedural features were significantly different, including gender, regurgitation etiology, and functional class (all p < 0.05). In-hospital outcomes were similarly satisfactory, with death occurring in 18 (2.4%) and 32 (2.9%, p = 0.561), respectively, and improvement in mitral regurgitation in 732 (97.4%) and 1078 (97.8%, p = 0.746), respectively. After a mean follow-up of 15 months, death occurred in 152 (20.2%) and 264 (24.0%), and cardiac death in 85 (11.3%) and 138 (12.5%), respectively (both p > 0.05). Rehospitalization for heart failure and the composite of cardiac death or rehospitalization for heart failure were significantly less common in octogenarians: 63 (8.4%) vs 156 (14.2%, p < 0.001), and 125 (16.6%) vs 242 (22.0%, p = 0.005), respectively. Multivariable analysis showed that these differences were largely due to confounding features, as after adjustment for baseline, clinical and imaging characteristics no significant difference was found for the above clinical endpoints.

CONCLUSIONS

Transcatheter mitral valve repair with the MitraClip in carefully selected octogenarians appears feasible and safe, and is associated with favorable clinical outcomes at mid-term follow-up.

Comparison of percutaneous MitraClip versus mitral valve surgery for severe mitral regurgitation: a meta-analysis: Mitraclip and mitral valve surgery meta-analysis

AIMS

Mitral valve surgery (MVS) is the gold-standard treatment for severe symptomatic mitral regurgitation. Percutaneous mitral valve interventions such as the MitraClip procedure offer another dimension to its management particularly in high-risk patients. We meta-analysed the outcomes of MitraClip and MVS.

METHODS AND RESULTS

PubMed, MEDLINE, Embase, Cochrane and Scopus from 1980/01-2019/06 were searched for eligible studies. Data were extracted and pooled using random-effects models. After screening 959 studies and reviewing 21 full-text articles, nine studies totalling 640 MitraClip and 531 MVS (91% valve repair) procedures were included in the meta-analysis. MitraClip patients were older, with a higher prevalence of previous cardiac surgery, coronary disease and a higher EuroSCORE (all p<0.05) than MVS patients. Pooled operative mortality was similar for MitraClip, 3%, versus MVS, 5%, odds ratio (OR): 0.58, 95%, CI: 0.28-1.19, as well as at 1 year mortality, OR: 1.09, CI: 0.71-1.68 and 3-year mortality, OR: 1.08, CI: 0.72-0.163. MitraClip patients had higher rates of early and late significant mitral regurgitation (MR) and more cardiovascular readmissions, while MVS had higher rates of in-hospital bleeding and pacemaker implantation (all p<0.05).

CONCLUSIONS

MitraClip patients had a higher baseline risk than MVS, but there were no significant differences in short- and long-term mortality. MitraClip patients had higher rates of cardiovascular admissions and significant MR post-operatively, while MVS patients had more procedural complications.

Stroke after transcatheter edge-to-edge mitral valve repair: a systematic review and meta-analysis

AIMS

The aim of this study was to assess the stroke rate after transcatheter mitral valve repair (TMVR) with the MitraClip, comparing it with surgical mitral valve repair (SMVR) and optimal medical treatment (OMT).

METHODS AND RESULTS

In December 2018, we systematically searched PubMed, Embase and Cochrane Controlled Register of Trials for studies comparing TMVR with SMVR and/or OMT for the treatment of severe mitral regurgitation. Random-effects and cumulative meta-analysis was performed. Ten studies were included (seven of TMVR versus SMVR and three of TMVR versus OMT), providing a total of 1,881 patients and 61 pooled strokes (16 in TMVR versus SMVR and 45 in TMVR versus OMT). There was no difference in stroke incidence between TMVR and SMVR (pooled OR 0.49 [0.17, 1.42], p=0.19). However, there was a trend towards a lower stroke risk in TMVR. For TMVR versus OMT, no difference in stroke rate was identified (pooled OR 1.09 [0.60, 1.97], p=0.79). Post-procedure de novo atrial fibrillation was more frequent in SMVR when compared with TMVR.

CONCLUSIONS

Despite both a low number of pooled stroke events and the failure to reach the pre-specified statistical significance, there was a trend for a lower post-procedure stroke rate in TMVR when compared with SMVR and a similar one between TMVR and OMT alone.

Contemporary Status of Percutaneous Transcatheter Edge-to-Edge Repair: Is It a Complement or Replacement to Mitral Surgery?

Transcatheter mitral valve repair devices borrow from the concept of surgical edge-to-edge approximation and are becoming increasingly used in patients with both primary and functional mitral regurgitation. The application of these new devices is expanding globally; however, debates between which patients are amenable to surgery vs. percutaneous approaches are ongoing. As new trials and regulatory approvals have evolved, the indications for transcatheter approaches have expanded, in a way that is complementaty to existing indications for surgical repair. In general, the treatment of mitral regurgitation should be stratified based on underlying pathophysiology and anatomy by a multidisciplinary team including cardiac surgeons and interventional cardiologists. This review aims to provide practical approaches to patient selection and treatment strategies for mitral regurgitation based on historical data and recently published trials, with a focus on the distinction between surgical and transcatheter mitral therapies.

Valvular Heart Disease in Patients ≥80 Years of Age

In the United States, the octogenarian population is projected to triple by 2050. With this aging population, the prevalence of valvular heart disease (VHD) is on the rise. The etiology, approach to treatment, and expected outcomes of VHD are different in the elderly compared with younger patients. Both stenotic and regurgitant lesions are associated with unfavorable outcomes if left untreated. Surgical mortality remains high due to multiple co-morbidities, and long-term survival benefit is dependent on many variables including valvular pathology. Quality of life is an important consideration in treatment decisions in this age group. Increasingly, octogenarian patients are receiving transcatheter therapies, with transcatheter aortic valve replacement having the greatest momentum. Numerous transcatheter devices for management of other valve lesions are currently in early clinical trials. This review will describe the epidemiology, etiology, diagnosis, and therapeutic options for VHD in the oldest old, with a focus on transcatheter technologies.

Can Elderly Patients with Severe Mitral Regurgitation Benefit from Trans-catheter Mitral Valve Repair?

Background and Objectives

Age is a traditional risk factor for open-heart surgery. The efficacy and safety of transcatheter edge-to-edge mitral valve repair, using MitraClip (Abbott Vascular), has been demonstrated in patients with severe mitral regurgitation (MR). Since octogenarians or older patients are usually deferred to receive open-heart surgery, the main interest of this study is to elucidate the procedural safety and long-term clinical impact of MitraClip in elderly patients.

Methods

Patients with symptomatic severe MR were evaluated by the heart team. For those with high or prohibitive surgical risks, transcatheter mitral valve repair was performed in hybrid operation room. Transthoracic echocardiography (TTE), blood tests, and six-minute walk test (6MWT) were performed before, 1-month, 6-months, and 1 year after index procedure.

Results

A total of 46 consecutive patients receiving MitraClip procedure were enrolled. Nineteen patients (84.2±4.0 years) were over 80-year-old and 27 (73.4±11.1 years) were younger than 80. Compare to baseline, the significant reduction in MR severity was achieved after the procedure and sustained. All the patients benefited from significant improvement in New York Heart Association functional class. The 6-minute walk test (6MWT) increased from 259±114 to 319±92 meters (p=0.03) at 1 year. The overall 1-year survival rate was 80% in the elderly and 88% in those <80 years, p=0.590. Baseline 6MWT was a predictor for all-cause mortality (odds ratio, 0.99; 95% confidence interval, 0.982–0.999; p=0.026) after the MitraClip procedure.

Conclusions

Trans-catheter edge-to-edge mitral valve repairs are safe and have positive clinical impact in subjects with severe MR, even in advanced age.

Transcatheter or surgical repair for degenerative mitral regurgitation in elderly patients: A propensity-weighted analysis

OBJECTIVE

To compare the outcomes of MitraClip and surgical mitral repair in low-intermediate risk elderly patients affected by degenerative mitral regurgitation (DMR).

METHODS

We retrospectively selected patients aged ≥75 years, with Society of Thoracic Surgeons Predicted Risk Of Mortality (STS-PROM) <8%, submitted to MitraClip (n = 100) or isolated surgical repair (n = 206) for DMR at 2 centers between January 2005 and May 2017. To adjust for baseline imbalances, we used a propensity score model for average treatment effect on survival.

RESULTS

After weighting, MitraClip showed fewer postoperative complications (P < .05) but increased residual mitral regurgitation (MR) ≥2 (27.0% vs 2.8%, P < .001) compared with surgery. One-year survival was greater after MitraClip compared with surgery (97.6% vs 95.3%, hazard ratio [HR], 0.09; confidence interval [CI], 0.02-0.37, P = .001), whereas 5-year survival was lower (34.5% vs 82.2% respectively, HR, 4.12; CI, 2.31-7.34, P < .001). Greater STS-PROM (HR, 1.18; CI, 1.12-1.24, P < .001) and MR ≥3+ recurrence (HR, 2.18; CI, 1.07-4.48, P = .033) were associated with reduced survival. 5-year MR ≥3+ was more frequent after MitraClip compared with surgery: 36.9% versus 3.9%, odds ratio, 11.4; CI, 4.40-29.68, P < .001.

CONCLUSIONS

In elderly patients affected by DMR and STS-PROM <8%, the average effect of MitraClip resulted in lower acute postoperative complications and improved 1-year survival compared with surgery. However, MitraClip was associated with greater MR recurrence and reduced survival beyond 1 year. Long-term survival was impaired by patients' greater risk profile and MR recurrence. Early results are promising, but in the setting of operable patients with life expectancy beyond 1 year, the quality bar for transcatheter mitral repair needs to be raised.

Effect of saline administration on left atrial pressure during transcatheter mitral valve repair

OBJECTIVES

To measure the intraprocedural change in left atrial pressure (LAP) with saline administration during transcatheter mitral valve repair (TMVR).

BACKGROUND

TMVR with MitraClip offers an alternative to surgery in select patients. During this procedure, large volumes of fluid are routinely administered with anesthesia and to facilitate transcatheter valve repair. LAP, a measure used to guide repair, may thereby change as a result of volume expansion, suggesting a need for continuous intracardiac pressure monitoring.

METHODS

Consecutive patients with severe mitral regurgitation underwent TMVR with MitraClip and continuous LAP monitoring through a dedicated sampling catheter. Specific LAP values were acquired immediately after transseptal access; before first clip deployment; and after deployment of the last clip.

RESULTS

151 patients (age 80 ± 8 years, 64% male) underwent TMVR with MitraClip and continuous LAP monitoring. Mean LAP and v-wave pressure increased significantly from baseline to pre-MitraClip deployment (P < 0.0001) and decreased significantly from deployment to procedure end (P < 0.0001). Linear regression of v-wave pressure change (from procedure start to clip deployment) relative to volume administration yielded a significantly nonzero slope (0.28 mmHg/min, P < 0.0001, r = 0.30).

CONCLUSION

Fluid administration during TMVR leads to time-dependent increases in LAP. Such intraprocedural change underscores the need for targeted, if not continuous, LAP measurement during TMVR to optimize MitraClip placement and mitral regurgitation reduction.

[The Old-Age Heart]

The Old-Age Heart Abstract. Knowledge of cardiovascular changes in old age and their therapeutic options is important. Old age can lead to hypertrophy of the left ventricle, diastolic dysfunction, heart valve changes and pulmonary hypertension. Patients often develop arterial hypertension. Valvular changes are common in people over 100 years of age (aortic stenosis and mitral insufficiency). The risk of coronary heart disease is 35 % for men and 24 % for women. In old age, sinus node dysfunction and atrial fibrillation are common. 25 % of all strokes are cardiac embolisms in atrial fibrillation. Cardiac interventions in the elderly are increasingly frequent and include coronary catheter revascularization or valve interventions (percutaneous aortic valve replacement or MitraClip). Optimal therapy in old age includes not only cardiovascular interventions also include drugs and a lifestyle modification and mainly serves to improve the quality of life.

Predictors of survival in octogenarians after mitral valve surgery for degenerative disease: The Mitral Surgery in Octogenarians study

OBJECTIVES

An increasing number of octogenarians are referred to undergo mitral valve surgery for degenerative disease, and percutaneous approaches are being increasingly used in this subgroup of patients. We sought to determine the survival and its predictors after Mitral Valve Surgery in Octogenarians (MiSO) in a multicenter UK study of high-volume specialized centers.

METHODS

Pooled data from 3 centers were collected retrospectively. To identify the predictors of short-term composite outcome of 30 days mortality, acute kidney injury, and cerebrovascular accident, a multivariable logistic regression model was developed. Multiple Cox regression analysis was performed for late mortality. Kaplan-Meier curves were generated for long-term survival in various subsets of patients. Receiver operating characteristic analysis was done to determine the predictive power of the logistic European System for Cardiac Operative Risk Evaluation.

RESULTS

A total of 247 patients were included in the study. The median follow-up was 2.9 years (minimum 0, maximum 14 years). A total of 150 patients (60.7%) underwent mitral valve repair, and 97 patients (39.3%) underwent mitral valve replacement. Apart from redo cardiac surgery (mitral valve repair 6 [4%] vs mitral valve replacement 11 [11.3%], P = .04) and preoperative atrial fibrillation (mitral valve repair 79 [52.6%] vs mitral valve replacement 34 [35.1%], P < .01), there was no significant difference in terms of any other preoperative characteristics between the 2 groups. Patient operative risk, as estimated by logistic European System for Cardiac Operative Risk Evaluation, was lower in the mitral valve repair group (10.2 ± 11.8 vs 13.7 ± 15.2 in mitral valve replacement; P = .07). No difference was found between groups for duration of cardiopulmonary bypass and aortic crossclamp times. The 30-day mortality for the whole cohort was 13.8% (mitral valve repair 4.7% vs mitral valve replacement 18.6%; P < .01). No differences were found in terms of postoperative cerebrovascular accident (2% vs 3.1%; P = .9), acute kidney injury requiring dialysis (6.7% vs 13.4%; P = .12), and superficial or deep sternal wound infection (10% vs 16.5%, P = .17; 2% vs 3.1%, P = .67, respectively). The final multiple regression model for short-term composite outcome included previous cardiac surgery (odds ratio [OR], 4.47; 95% confidence interval [CI], 1.37-17.46; P = .02), intra-aortic balloon pump use (OR, 4.77; 95% CI, 1.67-15.79; P < .01), and mitral valve replacement (OR, 7.7; 95% CI, 4.04-14.9; P < .01). Overall survival for the entire cohort at 1, 5, and 10 years was 82.4%, 63.7%, and 45.5% (mitral valve repair vs mitral valve replacement: 89.9% vs 70.7% at 1 year, 69.6% vs 54% at 5 years, and 51.8% vs 35.5% at 10 years; P = .0005). Cox proportional hazard model results showed mitral valve replacement (hazard ratio, 1.88; 95% CI, 1.22-2.89; P < .01) and intra-aortic balloon pump use (hazard ratio, 2.54; 95% CI, 1.26-5.13; P < .01) to be independent predictor factors affecting long-term survival. Logistic European System for Cardiac Operative Risk Evaluation did not perform well in predicting early mortality (area under the curve, 0.57%).

CONCLUSIONS

In octogenarians, mitral valve repair for degenerative disease is associated with good survival and remains the gold standard, whereas mitral valve replacement is still associated with significant mortality. Logistic European System for Cardiac Operative Risk Evaluation was unable to predict early mortality in our cohort of patients. Larger international multicenter registries are required to optimize the decision-making process in such a high-risk subgroup.

Established interventions for mitral valve regurgitation. Current evidence

Severe mitral regurgitation (MR) is a growing medical challenge in today's aging population, leading to increased health expenditure due to the resultant morbidity and mortality. Surgery, either replacement or repair, has been the mainstay of therapy for primary MR. In high-risk or inoperable patients, treatment was limited to medical therapy until 2008. Since then, alternative percutaneous therapies have been introduced and have proven to be safe and effective in patients with secondary MR. Edge-to-edge repair with the MitraClip system is applied worldwide for primary and secondary MR. Randomized data do not support its application in low-risk patients with primary MR. Results from ongoing and future randomized trials will clarify its impact on important clinical endpoints in high-risk and inoperable patients. The Carillon device is a percutaneous indirect annuloplasty technique introduced in 2009 for secondary MR. Clinical data for the novel Cardioband system, using a different intra-atrial annuloplasty technique, have been gathered from more than 40 patients and the system recently received CE mark approval. Other percutaneous repair devices and implantable valves are under development and may be introduced into clinical practice soon. The percutaneous interventional therapy of MR is a highly dynamic field of cardiovascular medicine and has the potential to improve quality of life as well as morbidity and mortality in selected patients.

A review of comparative studies of MitraClip versus surgical repair for mitral regurgitation

OBJECTIVES

We summarized comparative studies of MitraClip versus surgical repair for mitral regurgitation (MR) with a systematic literature search and meta-analytic estimates.

METHODS

MEDLINE, EMBASE, and the Cochrane Central Register of Controlled Trials were searched through June 2016. Eligible studies were randomized controlled or observational comparative studies of MitraClip versus surgical repair enrolling patients with MR and reporting early (30-day or in-hospital) or late (≥6-month including early) all-cause mortality. For each study, data regarding all-cause mortality and incidence of recurrent >2+ MR in both groups were used to generate odds ratios (ORs). Alternatively, ORs or hazard ratios (HRs) for mortality and recurrent MR themselves were directly abstracted from each study.

RESULTS

Eight reports of 7 studies comparing MitraClip with surgical repair enrolling a total of 1015 patients with MR were identified and included. Pooled analyses demonstrated significantly higher age and logistic European System of Cardiac Operative Risk Evaluation and significantly lower ejection fraction in the MitraClip than surgical repair group, no significant difference in rate of women and patients with New York Heart Association functional class of >II, no statistically significant difference in early- (OR, 0.54; p=0.08) and late-mortality (HR/OR, 1.17; p=0.46), and significantly higher incidence of recurrent MR in the MitraClip than surgical repair group (HR/OR, 4.80; p<0.00001).

CONCLUSIONS

In patients with MR, the MitraClip procedure achieves similar survival to surgical MV repair despite higher risk profiles. Recurrent MR, however, occurs more frequently (4.8-fold) after the MitraClip than surgical repair.

Novel therapeutic strategies for Alzheimer's disease based on the forgotten reproductive hormones

The relationship between hormones and Alzheimer's disease (AD) has been intensely researched. While the majority of this work has focused on the sex steroids, estrogens, and more recently androgens, a serendipitous patient encounter led one of us (R.L.B.) to question whether other hormones of the hypothalamic-pituitary-gonadal axis might play a role in the pathogenesis of AD. The age-related decline in reproductive function results in a dramatic decrease in serum estrogen and testosterone concentrations and an equally dramatic compensatory increase in serum gonadotropin concentrations. Indeed, there is growing evidence that the gonadotropin luteinizing hormone, which regulates serum estrogen and testosterone concentrations, is an important causative factor in the development of AD. This review provides information supporting the 'gonadotropin hypothesis'. We put forth a novel mechanism of how changes in serum luteinizing hormone concentrations could contribute to the pathogenesis of AD and discusses potential therapeutic anti-gonadotropin compounds.