Jonathan Gordon Howlett

Dr. Jonathan Gordon Howlett

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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22 December 2020 in European Heart Journal
Verified
Journal Article
Closed access
WAWilliam T Abraham
William T Abraham
JLJoAnn Lindenfeld
JoAnn Lindenfeld
PPPiotr Ponikowski
Piotr Ponikowski
PAPiergiuseppe Agostoni
Piergiuseppe Agostoni
JBJaved Butler
Javed Butler
SAStefan D Anker
Stefan D Anker
Aims: The EMPERIAL (Effect of EMPagliflozin on ExeRcise ability and HF symptoms In patients with chronic heArt faiLure) trials evaluated the effects of empagliflozin on exercise ability and patient-reported outcomes in heart failure (HF) with reduced and preserved ejection fraction (EF), with and without type 2 diabetes (T2D), reporting, for the first time, the effects of sodium-glucose co-transporter-2 inhibition in HF with preserved EF (HFpEF). Methods and results: HF patients with reduced EF (HFrEF) (≤40%, N = 312, EMPERIAL-Reduced) or preserved EF (>40%, N = 315, EMPERIAL-Preserved), with and without T2D, were randomized to empagliflozin 10 mg or placebo for 12 weeks. The primary endpoint was 6-minute walk test distance (6MWTD) change to Week 12. Key secondary endpoints included Kansas City Cardiomyopathy Questionnaire Total Symptom Score (KCCQ-TSS) and Chronic Heart Failure Questionnaire Self-Administered Standardized format (CHQ-SAS) dyspnoea score. 6MWTD median (95% confidence interval) differences, empagliflozin vs. placebo, at Week 12 were −4.0 m (−16.0, 6.0; P = 0.42) and 4.0 m (−5.0, 13.0; P = 0.37) in EMPERIAL-Reduced and EMPERIAL-Preserved, respectively. As the primary endpoint was non-significant, all secondary endpoints were considered exploratory. Changes in KCCQ-TSS and CHQ-SAS dyspnoea score were non-significant. Improvements with empagliflozin in exploratory pre-specified analyses of KCCQ-TSS responder rates, congestion score, and diuretic use in EMPERIAL-Reduced are hypothesis generating. Empagliflozin adverse events were consistent with those previously reported. Conclusion: The primary outcome for both trials was neutral. Empagliflozin was well tolerated in HF patients, with and without T2D, with a safety profile consistent with that previously reported in T2D. Hypothesis-generating improvements in exploratory analyses of secondary endpoints with empagliflozin in HFrEF were observed.

28 March 2020 in European Heart Journal
Verified
Journal Article
Open access
KDKieran F Docherty
Kieran F Docherty
PJPardeep S Jhund
Pardeep S Jhund
SISilvio E Inzucchi
Silvio E Inzucchi
LKLars Køber
Lars Køber
MKMikhail N Kosiborod
Mikhail N Kosiborod
JMJohn J V McMurray
John J V McMurray
Aims: In the DAPA-HF trial, the SGLT2 inhibitor dapagliflozin reduced the risk of worsening heart failure (HF) and death in patients with HF and reduced ejection fraction. We examined whether this benefit was consistent in relation to background HF therapy. Methods and results: In this post hoc analysis, we examined the effect of study treatment in the following yes/no subgroups: diuretic, digoxin, mineralocorticoid receptor antagonist (MRA), sacubitril/valsartan, ivabradine, implanted cardioverter-defibrillating (ICD) device, and cardiac resynchronization therapy. We also examined the effect of study drug according to angiotensin-converting enzyme inhibitor/angiotensin receptor blocker dose, beta-blocker (BB) dose, and MRA (≥50% and <50% of target dose). We analysed the primary composite endpoint of cardiovascular death or a worsening HF event. Most randomized patients (n = 4744) were treated with a diuretic (84%), renin–angiotensin system (RAS) blocker (94%), and BB (96%); 52% of those taking a BB and 38% taking a RAS blocker were treated with ≥50% of the recommended dose. Overall, the dapagliflozin vs. placebo hazard ratio (HR) was 0.74 [95% confidence interval (CI) 0.65–0.85] for the primary composite endpoint (P < 0.0001). The effect of dapagliflozin was consistent across all subgroups examined: the HR ranged from 0.57 to 0.86 for primary endpoint, with no significant randomized treatment-by-subgroup interaction. For example, the HR in patients taking a RAS blocker, BB, and MRA at baseline was 0.72 (95% CI 0.61–0.86) compared with 0.77 (95% CI 0.63–0.94) in those not on all three of these treatments (P-interaction 0.64). Conclusion: The benefit of dapagliflozin was consistent regardless of background therapy for HF.

21 August 2020 in European Heart Journal
Verified
Journal Article
Open access
MSMatteo Serenelli
Matteo Serenelli
MBMichael Böhm
Michael Böhm
SISilvio E Inzucchi
Silvio E Inzucchi
LKLars Køber
Lars Køber
MKMikhail N Kosiborod
Mikhail N Kosiborod
JMJohn J V McMurray
John J V McMurray
Aims: Concern about hypotension often leads to withholding of beneficial therapy in patients with heart failure and reduced ejection fraction (HFrEF). We evaluated the efficacy and safety of dapagliflozin, which lowers systolic blood pressure (SBP),according to baseline SBP in Dapagliflozin and Prevention of Adverse Outcomes in Heart Failure trial (DAPA-HF). Methods and results: Key inclusion criteria were: New York Heart Association Class II−IV, left ventricular ejection fraction ≤ 40%, elevated N-terminal pro-B-type natriuretic peptide level, and SBP ≥95 mmHg. The primary outcome was a composite of worsening heart failure or cardiovascular death. The efficacy and safety of dapagliflozin were examined using SBP as both a categorical and continuous variable. A total of 1205 patients had a baseline SBP <110 mmHg; 981 ≥ 110 < 120; 1149 ≥ 120 < 130; and 1409 ≥ 130 mmHg. The placebo-corrected reduction in SBP from baseline to 2 weeks with dapagliflozin was −2.54 (−3.33 to −1.76) mmHg (P < 0.001), with a smaller between-treatment difference in patients in the lowest compared to highest SBP category. Patients in the lowest SBP category had a much higher rate (per 100 person-years) of the primary outcome [20.6, 95% confidence interval (95% CI) 17.6–24.2] than those in the highest SBP category (13.8, 11.7–16.4). The benefit and safety of dapagliflozin was consistent across the range of SBP; hazard ratio (95% CI) in each SBP group, lowest to highest: 0.76 (0.60–0.97), 0.76 (0.57–1.02), 0.81 (0.61–1.08), and 0.67 (0.51–0.87), P interaction = 0.78. Study drug discontinuation did not differ between dapagliflozin and placebo across the SBP categories examined. Conclusion: Dapagliflozin had a small effect on SBP in patients with HFrEF and was superior to placebo in improving outcomes, and well tolerated, across the range of SBP included in DAPA-HF. Clinical Trial Registration: ClinicalTrials.gov NCT03036124.

1 March 2020 in Canadian Journal of Cardiology
Verified
Journal Article
Closed access
NFNowell M Fine
Nowell M Fine
MDMargot K. Davis
Margot K. Davis
KAKim Anderson
Kim Anderson
DDDiego H. Delgado
Diego H. Delgado
GGGenevieve Giraldeau
Genevieve Giraldeau
SZShelley Zieroth
Shelley Zieroth

1 April 2010 in Canadian Journal of Cardiology
Verified
Journal Article
Closed access
JHJonathan Gordon Howlett
Jonathan Gordon Howlett
RMRobert S. McKelvie
Robert S. McKelvie
JCJeannine Costigan
Jeannine Costigan
ADAnique Ducharme
Anique Ducharme
EEEstrellita Estrella-Holder
Estrellita Estrella-Holder
SZShelley Zeiroth
Shelley Zeiroth

1 March 2016 in Canadian Journal of Cardiology
Verified
Journal Article
Closed access
JHJonathan Gordon Howlett
Jonathan Gordon Howlett
MCMichael Chan
Michael Chan
JEJustin Ezekowitz
Justin Ezekowitz
KHKaren Harkness
Karen Harkness
GHGeorge A. Heckman
George A. Heckman
SZShelley Zieroth
Shelley Zieroth