Kristina Kudelko

The Finland-United States investigation of non-insulin-dependent diabetes mellitus genetics (FUSION) study. I. An autosomal genome scan for genes that predispose to type 2 diabetes

We performed a genome scan at an average resolution of 8 cM in 719 Finnish sib pairs with type 2 diabetes. Our strongest results are for chromosome 20, where we observe a weighted maximum LOD score (MLS) of 2.15 at map position 69.5 cM from pter and secondary weighted LOD-score peaks of 2.04 at 56.5 cM and 1.99 at 17.5 cM. Our next largest MLS is for chromosome 11 (MLS = 1.75 at 84.0 cM), followed by chromosomes 2 (MLS = 0.87 at 5.5 cM), 10 (MLS = 0.77 at 75.0 cM), and 6 (MLS = 0.61 at 112.5 cM), all under an additive model. When we condition on chromosome 2 at 8.5 cM, the MLS for chromosome 20 increases to 5.50 at 69.0 cM (P=.0014). An ordered-subsets analysis based on families with high or low diabetes-related quantitative traits yielded results that support the possible existence of disease-predisposing genes on chromosomes 6 and 10. Genomewide linkage-disequilibrium analysis using microsatellite marker data revealed strong evidence of association for D22S423 (P=.00007). Further analyses are being carried out to confirm and to refine the location of these putative diabetes-predisposing genes.

The Finland-United States investigation of non-insulin-dependent diabetes mellitus genetics (FUSION) study. II. An autosomal genome scan for diabetes-related quantitative-trait loci

Type 2 diabetes mellitus is a complex disorder encompassing multiple metabolic defects. We report results from an autosomal genome scan for type 2 diabetes-related quantitative traits in 580 Finnish families ascertained for an affected sibling pair and analyzed by the variance components-based quantitative-trait locus (QTL) linkage approach. We analyzed diabetic and nondiabetic subjects separately, because of the possible impact of disease on the traits of interest. In diabetic individuals, our strongest results were observed on chromosomes 3 (fasting C-peptide/glucose: maximum LOD score [MLS] = 3.13 at 53.0 cM) and 13 (body-mass index: MLS = 3.28 at 5.0 cM). In nondiabetic individuals, the strongest results were observed on chromosomes 10 (acute insulin response: MLS = 3.11 at 21.0 cM), 13 (2-h insulin: MLS = 2.86 at 65.5 cM), and 17 (fasting insulin/glucose ratio: MLS = 3.20 at 9.0 cM). In several cases, there was evidence for overlapping signals between diabetic and nondiabetic individuals; therefore we performed joint analyses. In these joint analyses, we observed strong signals for chromosomes 3 (body-mass index: MLS = 3.43 at 59.5 cM), 17 (empirical insulin-resistance index: MLS = 3.61 at 0.0 cM), and 19 (empirical insulin-resistance index: MLS = 2.80 at 74.5 cM). Integrating genome-scan results from the companion article by Ghosh et al., we identify several regions that may harbor susceptibility genes for type 2 diabetes in the Finnish population.

Characteristics and Outcome After Hospitalization for Acute Right Heart Failure in Patients With Pulmonary Arterial Hypertension

Background— Although much is known about the risk factors for poor outcome in patients hospitalized with acute heart failure and left ventricular dysfunction, much less is known about the syndrome of acute heart failure primarily affecting the right ventricle (acute right heart failure). Methods and Results— By using Stanford Hospitals pulmonary hypertension database, we identified consecutive acute right heart failure hospitalizations in patients with PAH. We used longitudinal regression analysis with the generalized estimating equations method to identify factors associated with an increased likelihood of 90-day mortality or urgent transplantation. From June 1999 to September 2009, 119 patients with PAH were hospitalized for acute right heart failure (207 episodes). Death or urgent transplantation occurred in 34 patients by 90 days of admission. Multivariable analysis identified a higher respiratory rate on admission (>20 breaths per minute; OR, 3.4; 95% CI, 1.5–7.8), renal dysfunction on admission (glomerular filtration rate <45 mL/min per 1.73 m2; OR, 2.7; 95% CI, 1.2–6.3), hyponatremia (serum sodium ⩽136 mEq/L; OR, 3.6; 95% CI, 1.7–7.9), and tricuspid regurgitation severity (OR, 2.5 per grade; 95% CI, 1.2–5.5) as independent factors associated with an increased likelihood of death or urgent transplantation. Conclusions— These results highlight the high mortality after hospitalizations for acute right heart failure in patients with PAH. Factors identifiable within hours of hospitalization may help predict the likelihood of death or the need for urgent transplantation in patients with PAH.

Pulmonary Hypertension Associated With Left Heart Disease: Characteristics, Emerging Concepts, and Treatment Strategies

Left heart disease (LHD) represents the most common causes of pulmonary hypertension (PH). Whether caused by systolic or diastolic dysfunction or valvular heart disease, a hallmark of PH associated with LHD is elevated left atrial pressure. In all cases, the increase in left atrial pressure causes a passive increase in pulmonary pressure. In some patients, a superimposed active component caused by pulmonary arterial vasoconstriction and vascular remodeling may lead to a further increase in pulmonary arterial pressure. When present, PH is associated with a worse prognosis in patients with LHD. In addition to local abnormalities in nitric oxide and endothelin production, gene modifiers such as serotonin polymorphisms may be associated with the pathogenesis of PH in LHD. Optimizing heart failure regimens and corrective valve surgery represent the cornerstone of the treatment of PH in LHD. Recent studies suggest that sildenafil, a phosphodiesterase-5 inhibitor, is a promising agent in the treatment of PH in LHD. Unloading the left ventricle with circulatory support may also reverse severe PH in patients with end-stage heart failure allowing candidacy to heart transplantation.

Current Clinical Management of Pulmonary Arterial Hypertension

During the past 2 decades, there has been a tremendous evolution in the evaluation and care of patients with pulmonary arterial hypertension (PAH). The introduction of targeted PAH therapy consisting of prostacyclin and its analogs, endothelin antagonists, phosphodiesterase-5 inhibitors, and now a soluble guanylate cyclase activator have increased therapeutic options and potentially reduced morbidity and mortality; yet, none of the current therapies have been curative. Current clinical management of PAH has become more complex given the focus on early diagnosis, an increased number of available therapeutics within each mechanistic class, and the emergence of clinically challenging scenarios such as perioperative care. Efforts to standardize the clinical care of patients with PAH have led to the formation of multidisciplinary PAH tertiary care programs that strive to offer medical care based on peer-reviewed evidence-based, and expert consensus guidelines. Furthermore, these tertiary PAH centers often support clinical and basic science research programs to gain novel insights into the pathogenesis of PAH with the goal to improve the clinical management of this devastating disease. In this article, we discuss the clinical approach and management of PAH from the perspective of a single US-based academic institution. We provide an overview of currently available clinical guidelines and offer some insight into how we approach current controversies in clinical management of certain patient subsets. We conclude with an overview of our program structure and a perspective on research and the role of a tertiary PAH center in contributing new knowledge to the field.

Safety and efficacy of transition from systemic prostanoids to inhaled treprostinil in pulmonary arterial hypertension.

Pulmonary arterial hypertension (PAH) is a disease characterized by increased pulmonary pressures and chronic right heart failure. Therapies for moderate and severe PAH include subcutaneous (SQ) and intravenous (IV) prostanoids that improve symptoms and quality of life. However, treatment compliance can be limited by severe side effects and complications related to methods of drug administration. Inhaled prostanoids, which offer the advantage of direct delivery of the drug to the pulmonary circulation without need for invasive approaches, may serve as an alternative for patients unable to tolerate SQ/IV therapy. In this retrospective cohort study we collected clinical, hemodynamic, and functional data from 18 clinically stable patients with World Health Organization group I PAH seen in 6 large national PAH centers before and after transitioning to inhaled treprostinil from IV/SQ prostanoids. Before transition 15 patients had been receiving IV or SQ treprostinil (mean dose 73 ng/kg/min) and 3 patients had been on IV epoprostenol (mean dose 10 ng/kg/min) for an average duration of 113 ± 80 months. Although most patients who transitioned to inhaled treprostinil demonstrated no statistically significant worsening of hemodynamics or 6-minute walk distance, a minority demonstrated worsening of New York Heart Association functional class over a 7-month period. In conclusion, although transition of patients from IV/SQ prostanoids to inhaled treprostinil appears to be well tolerated in clinically stable patients, they should remain closely monitored for signs of clinical decompensation.

Incidence, Correlates, and Consequences of Acute Kidney Injury in Patients With Pulmonary Arterial Hypertension Hospitalized With Acute Right-Side Heart Failure

BACKGROUND Though much is known about the prognostic influence of acute kidney injury (AKI) in left-side heart failure, much less is known about AKI in patients with pulmonary arterial hypertension (PAH). METHODS AND RESULTS We identified consecutive patients with PAH who were hospitalized at Stanford Hospital for acute right-side heart failure. AKI was diagnosed according to the criteria of the Acute Kidney Injury Network. From June 1999 to June 2009, 105 patients with PAH were hospitalized for acute right-side heart failure (184 hospitalizations). AKI occurred in 43 hospitalizations (23%) in 34 patients (32%). The odds of developing AKI were higher among patients with chronic kidney disease (odds ratio [OR] 3.9, 95% confidence interval [CI] 1.8-8.5), high central venous pressure (OR 1.8, 95% CI 1.1-2.4, per 5 mm Hg), and tachycardia on admission (OR 4.3, 95% CI 2.1-8.8). AKI was strongly associated with 30-day mortality after acute right-side heart failure hospitalization (OR 5.3, 95% CI 2.2-13.2). CONCLUSIONS AKI is relatively common in patients with PAH and associated with a short-term risk of death.

Features and Outcomes of Methamphetamine-associated Pulmonary Arterial Hypertension

Rationale: Although amphetamines are recognized as “likely” agents to cause drug‐ and toxin‐associated pulmonary arterial hypertension (PAH), (meth)amphetamine‐associated PAH (Meth‐APAH) has not been well described. Objectives: To prospectively characterize the clinical presentation, histopathology, and outcomes of Meth‐APAH compared with those of idiopathic PAH (iPAH). Methods: We performed a prospective cohort study of patients with Meth‐APAH and iPAH presenting to the Stanford University Pulmonary Hypertension Program between 2003 and 2015. Clinical, pulmonary angiography, histopathology, and outcomes data were compared. We used data from the Healthcare Cost and Utilization Project to estimate the epidemiology of PAH in (meth)amphetamine users hospitalized in California. Measurements and Main Results: The study sample included 90 patients with Meth‐APAH and 97 patients with iPAH. Patients with Meth‐APAH were less likely to be female, but similar in age, body mass index, and 6‐minute‐walk distance to patients with iPAH. Patients with Meth‐APAH reported more advanced heart failure symptoms, had significantly higher right atrial pressure (12.7 ± 6.8 vs. 9.8 ± 5.1 mm Hg; P = 0.001), and had lower stroke volume index (22.2 ± 7.1 vs. 25.5 ± 8.7 ml/m2; P = 0.01). Event‐free survival in Meth‐APAH was 64.2%, 47.2%, and 25% at 2.5, 5, and 10 years, respectively, representing more than double the risk of clinical worsening or death compared with iPAH (hazard ratio, 2.04; 95% confidence interval, 1.28–3.25; P = 0.003) independent of confounders. California data demonstrated a 2.6‐fold increase in risk of PAH diagnosis in hospitalized (meth)amphetamine users. Conclusions: Meth‐APAH is a severe and progressive form of PAH with poor outcomes. Future studies should focus on mechanisms of disease and potential therapeutic considerations.

Drugs and toxins-associated pulmonary arterial hypertension: lessons learned and challenges ahead.

Since the identification of the link between pulmonary arterial hypertension (PAH) and exposure to certain drugs and toxins nearly fifty years ago, the expanding landscape of available pharmaceuticals and illicit drugs is further fueling this association. While some causative agents in drugs and toxins associated PAH (D&T‐APAH) have been identified, little is known about the exact biology and clinical implications of the disease. In this review, we discuss the historical evidence that links PAH with exposure to anorexinogens, cocaine, and methamphetamines and concentrate on what is known about potential pathogenesis, clinical manifestations, and current management. We conclude that future research should focus on studies looking at clinical outcome and susceptibility factors.

The Intersection of Genes and Environment: Development of Pulmonary Arterial Hypertension in a Patient With Hereditary Hemorrhagic Telangiectasia and Stimulant Exposure

Pulmonary arterial hypertension (PAH) is a rare complication of hereditary hemorrhagic telangiectasia (HHT). The triggers that promote the development of PAH in HHT remain poorly understood. We present the case of a 45-year-old woman with decompensated right-sided heart failure secondary to newly diagnosed PAH. The clinical diagnosis of HHT was confirmed on the basis of recurrent spontaneous epistaxis, multiple typical mucocutaneous telangiectasia, and the presence of pulmonary arteriovenous malformation. There was also a suggestive family history. The patient was discovered to have active and extensive stimulant abuse in addition to HHT. We concluded that there may be a temporal relationship between exposure to stimulants and development of PAH in a host with underlying gene mutation. This case highlights the paradigm of PAH development after environmental exposure in a genetically susceptible host.