IJCS | Volume 32, Nº4, July/August 2019

419 Gonzáles et al. Exercise and erectile dysfunction in heart Int J Cardiovasc Sci. 2019;32(4):418-427 Review Article satisfactory sexual intercourse. 15,16 In men with HF, there is a high prevalence of ED, higher than in healthy men of the same age group (37% vs 17%). 14 ED has been associated with the pathophysiological mechanisms of the HF syndrome and to the side effects of drug treatment. 12,13 Additionally, the degree of ED can be used as prognosis and survival factor for these patients. 9 In HF, based on the high level of scientific evidence, physical exercise is a highly recommended therapeutic strategy, 17-21 with several beneficial effects. 22-24 In fact, physical exercise was shown to benefit erectile function (EF), 25,26 the inflammatory profile 27-28 and the modulation of the autonomic nervous system, 29-31 promoting improvement in QoL and a reduction in the morbidity and mortality rates of these individuals. 32-36 However, despite growing interest in the topic, with emergence of many observational studies, 3-5,9-14 there is still a lack of studies evaluating the effects of physical exercise on EF of these patients. In the current knowledge, it seems plausible the hypothesis that physical exercise is a valid therapeutic strategy for ED, by contributing to improvement of the QoL and prognosis of these patients. In addition, physical exercise improves cardiocirculatory performance leading to reduced dyspnea and fatigue symptoms, and less need for drugs. All these variables have been recognized as aggravating factors of SD. 12-14 Therefore, this study aimed to evaluate the effects of physical exercise on EF in individuals with HF, using a systematic review. Methods Search strategies This was a systematic review conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyzes) 37 recommendations and registered in the PROSPERO platform (International Prospective Register of Systematic Reviews), under the number CRD42018090028. Thesearchforarticleswasconductedbytwoindependent researchers in the electronic databases (PubMed, LILACS, Cochrane-Library, Science Direct) databases from inception until October 2018. The study was structured using the PICO – acronym for Population, Intervention, Comparison (since “control”was not applicable to the goal of this study) and Outcomes – framework. 37 For the search in the PubMed and Cochrane databases, the following MeSH (Medical Subject Heading Terms) descriptors were used: “Heart Failure” OR “Congestive Heart Failure” OR “Cardiac Failure” AND “Exercise” OR “Exercise Therapy” OR “Aerobic Exercise” OR “Physical Exercise” OR “High-Intensity Interval Training” OR “High-Intensity Interval Training” OR “Resistance Training” OR “Strength Training” AND “Erectile Dysfunction” OR “Sexual Dysfunction, Physiological” OR “Penile Erection” OR “Genital Diseases, Male” OR “Impotence” OR “Sexual Dysfunction, Physiological” (Appendix I). These words were then found suitable for the search in the other databases (LILACS and Science Direct). In addition, a manual search was carried out for references cited in the articles. Also, a search for “gray” literature was performed in Google Scholar, and in the annals of the World Congress of Cardiology and the European Congress of Cardiology, since they are important events in the area of cardiology with strict selection criteria and representatives from all over the world. We also conducted a search for abstracts, due to the small number of papers on this topic. Eligibility criteria Inclusion criteria We included in the review controlled and randomized clinical trials, quasi-randomized controlled trials, comparative studies with or without concurrent controls, case studies, case series with 10 or more consecutive cases, abstracts and articles published in Portuguese, English, or Spanish. We selected studieswithadults (18years of age or older), with a diagnosis of HF, with reduced ejection fraction (≤ 45%) and functional classes I, II or III according toNYHA. Patients should have been submitted to interventionwith aerobic and/or resistance exercise of different intensities. Evaluation of sexual function shouldhave been performed by questionnaires or specific tests: stiffness and nocturnal penile tumescence test, drug-induced erection test, eco- doppler of the cavernous arteries, cavernosography by dynamic infusion, internal pudendal arteriography. 38 The minimumof 4-week of follow-up timewas considered for the time of intervention. Exclusion criteria Letter to the editor, guidelines, systematic reviews and meta-analyses were not included. We also did not include studies on HF patients with comorbidities